Graft modified ethylene/α-olefin copolymer

ABSTRACT

A graft-modified ethylene/α-olefin copolymer composition is prepared by graft copolymerizing an ethylene/α-olefin copolymer. The ethylene/α-olefin copolymer composition includes first and second ethylene/α-olefin copolymers. The copolymers are each prepared in the presence of a polymerization catalyst containing (a) an organoaluminum oxy compound and (b) for the first ethylene/α-olefin copolymer at least two kinds, and for the second ethylene/α-olefin copolymer one kind, of compounds of Group IV transition metals of the periodic table containing a ligand having a cyclopentadienyl skeleton. The ethylene/α-olefin copolymer composition may be blended with a polyolefin by mechanical or solution blending. The copolymer compositions have excellent moldability and heat stability properties and forms films having high transparency and mechanical strength.

This is a division of application Ser. No. 08/154,467, filed Nov. 18,1993, now U.S. Pat. No. 5,464,905 issued Nov. 7, 1995.

FIELD OF THE INVENTION

The present invention relates to an ethylene/α-olefin copolymercomposition having excellent properties such as high heat stability andgood moldability, a graft modified ethylene/α-olefin copolymercomposition having excellent properties such as good moldability andsufficient adhesion strength to metals or polar resins, an ethylenecopolymer composition comprising the graft modified ethylene/α-olefincopolymer composition and polyolefin, and a multi-stage olefinpolymerization process.

BACKGROUND OF THE INVENTION

Ethylene copolymers have heretofore been molded by various moldingmethods, and used in many fields. The requirement for thecharacteristics of the ethylene copolymers differs depending on themolding methods and uses. For example, when an inflation film is moldedat a high speed, it is necessary to select an ethylene copolymer havinga high melt tension compared with its molecular weight in order tostably conduct high speed molding without fluctuation or tearing ofbubbles. An ethylene copolymer is required to have similarcharacteristics in order to prevent sag or tearing in blow molding, orto suppress width shortage to the minimum range in T-die molding.Further, in extrusion molding, it is important to have small stressunder high shearing during extrusion in order to improve quality ofmolded article and reduce electric power consumption at molding.

By the way, Japanese Patent L-O-P Nos. 90810/1981 and 106806/1985propose a method for improving moldability by improving the melt tensionand die swell ratio of ethylene polymers obtained by using Ziegler typecatalysts, especially a titanium type catalyst.

The ethylene polymers obtained by using a titanium catalyst, however,especially the low density ethylene polymers generally have problemssuch as their broad composition distribution and stickiness of theirmolded articles such as films.

Of the ethylene polymers prepared by using the Ziegler type catalysts,those obtained by using chromium type catalysts are relatively excellentin melt tension but has a defect of poor heat stability. This is thoughtto be caused by that the chain terminals of the ethylene polymersprepared by using the chromium type catalysts tend to become unsaturatedbonds.

It is known that the ethylene polymers obtained by using a metallocenecatalyst from among the Ziegler type catalysts have merits such as anarrow composition distribution and a low stickiness of their moldedarticles such as films. However, it is described in, for exampleJapanese Patent L-O-P. No. 35007/1985, that an ethylene polymer obtainedby using a zirconocene compound formed from a cyclopentadienylderivative contains one terminal unsaturated bond per molecule, andhence this ethylene polymer is presumably poor in heat stabilitysimilarly to the above-mentioned ethylene polymer obtained by using thechromium type catalyst. Further, because of its narrow compositiondistribution, this ethylene polymer might show poor flowability duringthe extrusion molding.

Accordingly, it will industrially be of great value to provide anethylene copolymer, having good heat stability, high mechanical strengthand a narrow composition distribution.

By the way, ethylene copolymers generally have no polar group in themolecule and are inherently non-polar, so that they are insufficient inadhesion strength to highly polar materials such as metals and polarresins. For these reasons, when such ethylene copolymers are used bybonding them with the highly polar materials, it is necessary to subjectthe surface of the ethylene copolymer to a flame treatment, a coronadischarge treatment, a primer treatment or the like, and hence resultingin a problem of complicated operation.

Accordingly, it will also industrially be of great value to provide anethylene copolymer or an ethylene copolymer composition, which has highmelt tension, excellent flowability, good heat stability and highmechanical strength and shows sufficient adhesion strength to highlypolar materials.

OBJECT OF THE INVENTION

It is, therefore, an object of the present invention to provide anethylene/α-olefin copolymer composition of good moldability which iscapable for giving a film having high transparency and high mechanicalstrength, to provide a graft modified ethylene/α-olefin copolymercomposition of high heat stability and good moldability which is capablefor giving a film having high transparency and good adhesion to highlypolar materials, and to provide an ethylene copolymer compositioncontaining said graft modified ethylene/α-olefin copolymer composition.

It is another object of the invention to provide a process for preparingan ethylene/α-olefin copolymer composition of good moldability which iscapable of forming a film having high transparency and high mechanicalstrength.

SUMMARY OF THE INVENTION

The first ethylene/α-olefin copolymer composition according to thepresent invention is an ethylene/α-olefin copolymer compositioncomprising:

A1! an ethylene/α-olefin copolymer in an amount of 20 to 90% by weight,which is obtained by copolymerizing ethylene with an α-olefin of 3 to 20carbon atoms in the presence of a catalyst for olefin polymerizationcomprising (a) an organoaluminum oxy-compound and (b) at least two kindsof compounds of Group IV transition metals of the periodic tablecontaining-a ligand having a cyclopentadienyl skeleton, and which hassuch properties that:

(A-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(A-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g; and

B1! an ethylene/α-olefin copolymer in an amount of 10 to 80% by weight,which is different from the ethylene/α-olefin copolymer A1! and isobtained by copolymerizing ethylene with an α-olefin of 3 to 20 carbonatoms in the presence of a catalyst for olefin polymerization comprising(a) an organoaluminum oxy-compound and (b') a compound of Group IVtransition metal of the periodic table containing a ligand having acyclopentadienyl skeleton, and which has such properties that:

(B-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(B-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g.

In the invention, the above-mentioned at least two kinds of compounds(b) of Group IVB transition metals of the periodic table containing aligand having a cyclopentadienyl skeleton are preferably:

at least one kind of a transition metal compound represented by thefollowing formula b-I!:

    ML.sup.1.sub.x                                              b-I!

wherein M is a transition metal atom selected from Group IVB of theperiodic table, L¹ is a ligand coordinating to the transition metal atomM, at least two of L¹ are groups selected from a cyclopentadienyl group,a methylcyclopentadienyl group, an ethylcyclopentadienyl group and asubstituted cyclopentadienyl group having at least one substituent groupselected from a hydrocarbon group of 3 to 10 carbon atoms, L¹ other thanthe (substituted) cyclopentadienyl group is a hydrocarbon group of 1 to12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilylgroup, a halogen atom or a hydrogen atom, and X is a valence of thetransition metal atom M, and

at least one kind of a transition metal compound represented by thefollowing formula b-II!:

    ML.sup.2.sub.x                                              b-II!

wherein M is a transition metal atom selected from Group IVB of theperiodic table, L² is a ligand coordinating to the transition metalatom, at least two of L² are substituted cyclopentadienyl groups having,2-5 substituent groups selected from a methyl group and an ethyl group,L² other than the substituted cyclopentadienyl group is a hydrocarbongroup of 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, atrialkylsilyl group, a halogen atom or a hydrogen atom, and X is avalence of the transition metal atom M.

The second ethylene/α-olefin copolymer composition according to thepresent invention is an ethylene/α-olefin copolymer compositioncomprising:

A2! an ethylene/α-olefin copolymer in an amount of 20 to 90% by weight,which is a copolymer of ethylene with an α-olefin of 3 to 20 carbonatoms and has such properties that:

(A-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(A-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g,

(A-iii) the melt tension (MT (g)) at 190° C. and the melt flow rate(MFR) satisfy the relation

    MT>2.2×MFR.sup.-0.84,

(A-iv) the flow index (FI (l/sec)) defined by a shear rate which isgiven when a shear stress of molten copolymer at 190° C. reaches 2.4×10⁶dyne/cm² and the melt flow rate (MFR) satisfy the relation

    FI<150×MFR,

(A-v) the molecular weight distribution (Mw/Mn) measured by GPC is inthe range of 1.5 to 4, and

(A-vi) MT/(Mw/Mn) and FI/MFR satisfy the relation

    MT/(Mw/Mn)>0.03×FI/MFR-3.0

with the proviso that when the value of 0.03×FI/MFR-3.0 is less than 0,it is taken as 0; and

B1! an ethylene/α-olefin copolymer in an amount of 10 to 80% by weight,which is different from the ethylene/α-olefin copolymer A2! and isobtained by copolymerizing ethylene with an α-olefin of 3 to 20 carbonatoms in the presence of a catalyst for olefin polymerization comprising(a) an organoaluminum oxy-compound and (b') a compound of Group IVtransition metal of the periodic table containing a ligand having acyclopentadienyl skeleton, and which has such properties that:

(B-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(B-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g.

The ethylene/α-olefin copolymer composition of the invention isexcellent in heat resistance and moldability. From this composition, afilm having high transparency, high mechanical strength and highblocking resistance can be produced.

The graft modified ethylene/α-olefin copolymer composition according tothe present invention is a graft modified ethylene/α-olefin copolymercomposition obtained by graft copolymerizing an ethylene/α-olefincopolymer composition with a polar monomer, wherein theethylene/α-olefin copolymer composition comprises:

A3! an ethylene/α-olefin copolymer in an amount of 20 to 90% by weight,which is obtained by copolymerizing ethylene with an α-olefin of 3 to 20carbon atoms in the presence of a catalyst for olefin polymerizationcomprising (a) an organoaluminum oxy-compound and (b') a compound ofGroup IV transition metal of the periodic table containing a ligandhaving a cyclopentadienyl skeleton, and which has such properties that:

(A-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(A-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g; and

B1! an ethylene/α-olefin copolymer in an amount of 10 to 80% by weight,which is different from the ethylene/α-olefin copolymer A3! and isobtained by copolymerizing ethylene with an α-olefin of 3 to 20 carbonatoms in the presence of a catalyst for olefin polymerization comprising(a) an organoaluminum oxy-compound and (b') a compound of Group IVtransition metal of the periodic table containing a ligand having acyclopentadienyl skeleton, and which has such properties that:

(B-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(B-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g.

The graft modified ethylene/α-olefin copolymer composition of theinvention is excellent in moldability. From this composition, a filmhaving high transparency and good adhesion to highly polar materials canbe produced.

The ethylene copolymer composition according to the present invention isan ethylene copolymer composition comprising:

I! a graft modified ethylene/α-olefin copolymer composition obtained bygraft copolymerizing an ethylene/α-olefin copolymer composition with apolar monomer, said ethylene/α-olefin copolymer composition comprising:

A3! an ethylene/α-olefin copolymer in an amount of 20 to 90% by weight,which is obtained by copolymerizing ethylene with an α-olefin of 3 to 20carbon atoms in the presence of a catalyst for olefin polymerizationcomprising (a) an organoaluminum oxy-compound and (b') a compound ofGroup IV transition metal of the periodic table containing a ligandhaving a cyclopentadienyl skeleton, and which has such properties that:

(A-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(A-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g; and

B1! an ethylene/α-olefin copolymer in an amount of 10 to 80% by weight,which is different from the ethylene/α-olefin copolymer A3! and isobtained by copolymerizing ethylene with an α-olefin of 3 to 20 carbonatoms in the presence of a catalyst for olefin polymerization comprising(a) an organoaluminum oxy-compound and (b') a compound of Group IVtransition metal of the periodic table containing a ligand having acyclopentadienyl skeleton, and which has such properties that:

(B-i) the density is in the range of 0.850 to 0.980 g/cm³, and

(B-ii) the intrinsic viscosity η! as measured in decalin at 135° C. isin the range of 0.4 to 8 dl/g; and

II! polyolefin;

wherein a weight ratio ( I!: II!) between the graft modifiedethylene/α-olefin copolymer composition I! and the polyolefin II! is inthe range of 1:99 to 99:1.

The ethylene copolymer composition of the invention is excellent inmoldability. From this composition, a film having high transparency andgood adhesion to highly polar materials can be produced.

The multi-stage olefin polymerization process according to the presentinvention comprises:

a stage (1) of preparing an ethylene/α-olefin copolymer A1! bycopolymerizing ethylene with an α-olefin of 3 to 20 carbon atoms in thepresence of a catalyst for olefin polymerization (C1) comprising:

(a) an organoaluminum oxy-compound,

(b-I) at least one kind of a transition metal compound represented bythe above formula b-I!, and

(b-II) at least one kind of a transition metal compound represented bythe above formula b-II!; and

a stage (2) of preparing an ethylene/α-olefin copolymer B1! bycopolymerizing ethylene with an α-olefin of 3 to 20 carbon atoms in adifferent polymerizer from the polymerizer for the copolymerizationreaction of the stage (1) in the presence of a catalyst for olefinpolymerization (C2) comprising (a) an organoaluminum oxy-compound and(b') a compound of Group IV transition metal of the periodic tablecontaining a ligand having a cyclopentadienyl skeleton.

In the invention, the catalyst for olefin polymerization (C1) used forthe copolymerization stage (1) may be a catalyst further containing anorganoaluminum compound (c) in addition to the organoaluminumoxy-compound (a), the transition metal compound (b-I) and the transitionmetal compound (b-II); a solid catalyst in which the organoaluminumoxy-compound (a), the transition metal compound (b-I) and the transitionmetal compound (b-II) are supported on a carrier; or a prepolymerizedcatalyst obtained by prepolymerizing an olefin on a solid catalystcomponent, in said solid catalyst component the organoaluminumoxy-compound (a), the transition metal compound (b-I) and the transitionmetal compound (b-II) being supported on a carrier. Otherwise, thecatalyst (C1) may be a catalyst comprising the above-mentioned solidcatalyst (solid catalyst component) and the organoaluminum compound (c),or may be a catalyst comprising the above-mentioned prepolymerizedcatalyst (prepolymerized catalyst component) and the organoaluminumcompound (c).

Further, the catalyst for olefin polymerization (C2) used for thecopolymerization stage (2) may be a catalyst further containing anorganoaluminum compound (c) in addition to the organoaluminumoxy-compound (a) and the transition metal compound (b'); a solidcatalyst in which the organoaluminum oxy-compound (a) and the transitionmetal compound (b') are supported on a carrier; or a prepolymerizedcatalyst obtained by prepolymerizing an olefin on a solid catalystcomponent, in said solid catalyst component the organoaluminumoxy-compound (a) and the transition metal compound (b') being supportedon a carrier. Otherwise, the catalyst (C2) may be a catalyst comprisingthe above-mentioned solid catalyst (solid catalyst component) and theorganoaluminum compound (c), or may be a catalyst comprising theabove-mentioned prepolymerized catalyst (prepolymerized catalystcomponent) and the organoaluminum compound (c).

According to the multi-stage olefin polymerization process, there can beobtained an ethylene copolymer composition which has high heat stabilityand good moldability and from which a film having high transparency andhigh mechanical strength can be produced.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE is an explanatory view of a process for preparing a catalystfor olefin polymerization which is used for the multi-stage olefinpolymerization process according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The ethylene/α-olefin copolymer composition, the graft modifiedethylene/α-olefin copolymer composition, the ethylene copolymercomposition and the multi-stage olefin polymerization process, accordingto the present invention, will be described in detail hereinafter.

First, the ethylene/α-olefin copolymer composition of the invention willbe described below.

The first ethylene/α-olefin copolymer composition of the invention isformed from an ethylene/α-olefin copolymer A1! and an ethylene/α-olefincopolymer B1! which is different from the ethylene/α-olefin copolymerA1!, both being described later. The second ethylene/α-olefin copolymercomposition of the invention is formed from an ethylene/α-olefincopolymer A2! described later and the ethylene/α-olefin copolymer B1!which is different from the ethylene/α-olefin copolymer A2!.

Ethylene/α-olefin copolymer!

The ethylene/α-olefin copolymers A1! and A2! which form theethylene/α-olefin copolymer composition according to the invention areeach a random copolymer of ethylene with an α-olefin of 3 to 20 carbonatoms. Examples of the α-olefin of 3 to 20 carbon atoms employable forthe copolymerization with ethylene include propylene, 1-butene,1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene.

In each of the ethylene/α-olefin copolymers A1! and A2!, it is desiredthat constituent units derived from ethylene are present in an amount of50 to 100% by weight, preferably 55 to 99% by weight, more preferably 65to 98% by weight, most preferably 70 to 96% by weight, and constituentunits derived from an α-olefin of 3 to 20 carbon atoms are present in anamount of 0 to 50% by weight, preferably 1 to 45% by weight, morepreferably 2 to 35% by weight, most preferably 4 to 30% by weight.

The composition of an ethylene/α-olefin copolymer is generallydetermined by ¹³ C-NMR spectrum analysis of a sample prepared byhomogeneously dissolving about 200 mg of the copolymer in 1 ml ofhexachlorobutadiene in a sample tube having a diameter of 10 mm underthe conditions of a measuring temperature of 120° C., a measuringfrequency of 25.05 MHz, a spectrum width of 1,500 Hz, a pulse repetitionperiod of 4.2 sec and a pulse width of 6 μsec.

The ethylene/α-olefin copolymer A1! which forms the firstethylene/α-olefin copolymer composition according to the inventionpreferably has the following properties (A-i) and (A-ii), andparticularly preferably has the following properties (A-i) to (A-viii).The ethylene/α-olefin copolymer A2! which forms the secondethylene/α-olefin copolymer composition according to the inventionpreferably has the following properties (A-i) to (A-vi), andparticularly preferably has the following properties (A-i) to (A-viii).

(A-i) The density (d) is in the range of usually 0.850 to 0.980 g/cm³,preferably 0.880 to 0.940 g/cm³, more preferably 0.890 to 0.935 g/cm³,most preferably 0.900 to 0.930 g/cm³.

The density (d) is determined by means of a density gradient tube usinga strand, which has been obtained at the time of measurement of a meltflow rate (MFR) at 190° C. under a load of 2.16 kg and which is treatedby heating at 120° C. for 1 hour and slowly cooling to room temperatureover 1 hour.

(A-ii) The intrinsic viscosity η! as measured in decalin at 135° C. isin the range of usually 0.4 to 8 dl/g, preferably 1.25 to 8 dl/g, morepreferably 1.27 to 6 dl/g.

(A-iii) The melt tension (MT (g)) at 190° C. and the melt flow rate(MFR) satisfy the relation:

    MT>2.2×MFR.sup.-0.84,

preferably

    8.0×MFR.sup.-0.84 >MT>2.3×MFR.sup.-0.84,

more preferably

    7.5×MFR.sup.-0.84 >MT>2.5×MFR.sup.-0.84,

An ethylene/α-olefin copolymer having such properties shows goodmoldability because of high melt tension (MT).

The melt tension (MT (g)) is determined by measuring a stress given whena molten copolymer is stretched at a constant rate. That is, a powderypolymer was melted in a conventional manner, and the molten polymer waspelletized to give a measuring sample. Then, the MT of the sample wasmeasured under the conditions of a resin temperature of 190° C., anextrusion rate of 15 mm/min and a take-up rate of 10 to 20 m/min using aMT measuring apparatus (produced by Toyo Seiki Seisakusho K.K.) having anozzle diameter of 2.09 mmφ and a nozzle length of 8 mm. During thepelletization, to the ethylene/α-olefin copolymer were added 0.05% byweight of tri(2,4-di-t-butylphenyl)phosphate as a secondary antioxidant,0.1% by weight ofn-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate as a heatstabilizer and 0.05% by weight of calcium stearate as a hydrochloricacid absorbent.

The melt flow rate (MFR) is determined in accordance with ASTM D1238-65Tunder the conditions of a temperature of 190° C. and a load of 2.16 kg.

(A-iv) The flow index (FI (l/sec)) defined by a shear rate which isgiven when a shear stress of a molten copolymer at 190° C. reaches2.4×10⁶ dyne/cm² and the melt flow rate (MFR) satisfy the relation:

    FI<150×MFR,

preferably

    FI<140×MFR,

more preferably

    FI<130×MFR.

The flow index (FI) is determined by extruding a resin from a capillarywhile changing a shear rate and measuring the shear rate given when theshear stress reaches the above-mentioned value. In this measurement, thesame sample as described in the above-mentioned MT measurement is used,and the FI is measured under the conditions of a resin temperature of190° C. and a shear stress of about 5×10⁴ to 3×10⁶ dyne/cm² using acapillary type flow property tester produced by Toyo Seiki SeisakushoK.K.

In the measurement, a diameter of the nozzle (capillary) is changed asfollows depending on the MFR (g/10 min) of the resin to be measured:

in the case of MFR>20 :0.5 mm

in the case of 20≧MFR>3 :1.0 mm

in the case of 3≧MFR>0.8 :2.0 mm, and

in the case of 0.8≧MFR 3.0 mm.

(A-v) The molecular weight distribution (Mw/Mn, Mw: weight-averagemolecular weight, Mn: number-average molecular weight) measured by GPCis in the range of 1.5 to 4.

The molecular weight distribution (Mw/Mn) was measured 20 in thefollowing manner using a measuring device of GPC-150C produced byMillipore Co.

This measurement was carried out using a column of TSK-GNH-HT having adiameter of 72 mm and a length of 600 mm at a column temperature of 140°C. In this measurement, 500 microliters of a sample having aconcentration of 0.1% by weight was introduced into the column in whicho-dichlorobenzene (available from Wako Junyaku Kogyo K.K.) as a mobilephase was moved at a moving rate of 1.0 ml/min. In the mobile phase,0.025% by weight of BHT (available from Takeda Chemical Industries,Ltd.) was contained as an antioxidant. A differential refractometer wasused as a detector. With respect to the standard polystyrene of Mw 1,000and Mw>4×10⁶, those available from Toso Co. were used, and with respectto the standard polystyrene of 1,000<Mw<4×10⁶, those available fromPressure Chemical Co. were used.

(A-vi) MT/(Mw/Mn) and FI/MFR satisfy the relation:

    MT/(Mw/Mn)>0.03×FI/MFR-3.0

with the proviso that when the value of 0.03×FI/MFR-3.0 is less than 0,it is taken as 0,

preferably

0.03×FI/MFR+1.0>MT/(Mw/Mn)>0.03×FI/MFR-2.8 with the proviso that whenthe value of 0.03×FI/MFR-2.8 is less than 0, it is taken as 0,

more preferably

0.03×FI/MFR+0.8>MT/(Mw/Mn)>0.03×FI/MFR-2.5 with the proviso that whenthe value of 0.03×FI/MFR-2.5 is less than 0, it is taken as 0.

With increase of the value of Mw/Mn, the value of MT becomes large, sothat an index of MT/(Mw/Mn) is used in order to reduce an influence ofthe Mw/Mn value on the MT value. Likewise, with increase of the value ofMFR, the value of FI becomes large, so that an index of FI/MFR is usedin order to reduce an influence of the MFR value on the FI value.

(A-vii) The temperature (Tm (° C.)) at which the endothermic curve ofthe copolymer measured by a differential scanning calorimeter (DSC)shows the maximum peak and the density (d) satisfy the relation:

    Tm<400×d-250,

preferably

    Tm<450×d-297,

more preferably

    Tm<500×d-344,

particularly preferably

    Tm<550×d-391.

The temperature (Tm (° C.)) at which the endothermic curve of anethylene/α-olefin copolymer measured by a differential scanningcalorimeter (DSC) shows the maximum peak is sought from an endothermiccurve obtained by filling about 5 mg of a sample in an aluminum pan,heating to 200° C. at a rate of 10 ° C./min, holding the sample at 200°C. for 5 minutes, lowering the temperature to room temperature at a rateof 20 ° C./min and then heating at a rate of 10 ° C./min. Thismeasurement is carried out using a DSC-7 type apparatus produced byPerkin Elmer Co.

(A-viii) The quantity fraction (W (% by weight)) of a n-decane-solublecomponent at room temperature (23° C.) and the density (d) satisfy therelation:

in the case of MFR≦10 g/10 min:

    W<80×exp(-100(d-0.88))+0.1,

preferably

    W<60×exp(-100(d-0.88))+0.1,

more preferably

    W<40×exp(-100(d-0.88))+0.1,

and

in the case of

    MFR>10 g/10 min:

    W<80×(MFR-9).sup.0.26 ×exp(-100(d-0.88))+0.1.

The measurement of the n-decane-soluble component quantity of anethylene/α-olefin copolymer (polymer having a smaller soluble componentquantity has a narrower composition distribution) is carried out byadding about 3 g of the copolymer to 450 ml of n-decane, dissolving thecopolymer at 145° C. cooling the resultant solution to 23° C., removinga n-decane-insoluble portion by filtration, and recovering an-decane-soluble portion from the filtrate.

It may be concluded that the ethylene/α-olefin copolymer which satisfiesthe above-mentioned relation between the temperature (Tm) at which theendothermic curve measured by a differential scanning calorimeter (DSC)shows the maximum peak and the density (d), and the relation between thequantity fraction (W) of the n-decane-soluble component and the density(d), has a narrow composition distribution.

The ethylene/α-olefin copolymers A1! and A2! having the above mentionedproperties can be prepared by copolymerizing ethylene with an α-olefinof 3 to 20 carbon atoms in the presence of a catalyst for olefinpolymerization comprising, for example, the organoaluminum oxy-compound(a) and at least two kinds of the compounds (b) of transition metal anda carrier, and if necessary, (c) an organoaluminum compound, allcomponents being described later, in such a manner that the resultantcopolymer has a density of 0.850 to 0.980 g/cm³.

Ethylene/α-olefin copolymer B1!!

The ethylene/α-olefin copolymer B1! which forms the ethylene/α-olefincopolymer composition according to the invention is a random copolymerof ethylene with an α-olefin of 3 to 20 carbon atoms. Examples of theα-olefin of 3 to 20 carbon atoms employable for the copolymerizationwith ethylene include propylene, 1-butene, 1-pentene, 1-hexene,4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene and 1-eicosene.

In the ethylene/α-olefin copolymer B1!, it is desired that constituentunits derived from ethylene are present in an amount of 50 to 100% byweight, preferably 55 to 99% by weight, more preferably 65 to 98% byweight, most preferably 70 to 96% by weight, and constituent unitsderived from an α-olefin of 3 to 20 carbon atoms are present in anamount of 0 to 50% by weight, preferably 1 to 45% by weight, morepreferably 2 to 35% by weight, most preferably 4 to 30% by weight.

The ethylene/α-olefin copolymer B1! preferably has the followingproperties (B-i) and (B-ii), and particularly preferably has thefollowing properties (B-i) to (B-iv).

(B-i) The density (d) is in the range of usually 0.850 to 0.980 g/cm³,preferably 0.910 to 0.960 g/cm³, more preferably 0.915 to 0.955 g/cm³,most preferably 0.920 to 0.950 g/cm³.

(B-ii) The intrinsic viscosity η! as measured in decalin at 135° C. isin the range of usually 0.4 to 8 dl/g, preferably 0.4 to 1.25 dl/g, morepreferably 0.5 to 1.23 dl/g.

(B-iii) The temperature (Tm (° C.)) at which the endothermic curve ofthe copolymer measured by a differential scanning calorimeter (DSC)shows the maximum peak and the density (d) satisfy the relation:

    Tm<400×d-250,

preferably

    Tm<450×d-297,

more preferably

    Tm<500×d-344,

particularly preferably

    Tm<550×d-391.

(B-iv) The quantity fraction (W (% by weight)) of A n-decane-solublecomponent at room temperature (23° C.) and the density (d) satisfy therelation:

in the case of

    MFR <10 g/10 min:

    W<80×exp(-100(d-0.88))+0.1,

preferably

    W<60×exp (-100 (d-0.88))+0.1,

more preferably

    W<40×exp (-100 (d-0.88))+0.1,

and

in the case of

    MFR>10 g/10 min:

    W<80×(MFR-9).sup.0.26 ×exp(-100 (d-0.88))+0.1.

It may be concluded that the ethylene/α-olefin copolymer B1! whichsatisfies the above-mentioned relation between the temperature (Tm) atwhich the endothermic curve measured by a differential scanningcalorimeter (DSC) shows the maximum peak and the density (d), and therelation between the quantity fraction (W) of the n-decane-solublecomponent and the density (d), has a narrow composition distribution.

The ethylene/α-olefin copolymer B1! having the above mentionedproperties can be prepared by copolymerizing ethylene with an α-olefinof 3 to 20 carbon atoms in the presence of a catalyst for olefinpolymerization comprising, for example, the organoaluminum oxy-compound(a), transition metal compound (b') and a carrier, and if necessary, (c)an organoaluminum compound in such a manner that the resultant copolymerhas a density of 0.850 to 0.980 g/cm³.

Hereinafter, the organoaluminum oxy-compound (a), the compound (b) of atransition metal in Group IVB of the periodic table containing a ligandhaving a cyclopentadienyl skeleton, the compound (b') of a transitionmetal in Group IVB Of the periodic table containing a ligand having acyclopentadienyl skeleton, a carrier and the organoaluminum compound (c)which are used in the preparation of ethylene/α-olefin copolymers A1!,A2! and B1! contained in the ethylene/α-olefin composition of thepresent invention are explained below.

The organoaluminum oxy-compound (a) hereinafter sometimes referred to as"component (a)"! used in the preparation of the ethylene/α-olefincopolymers A1!, A2! and B1! may be a known benzene-soluble aluminoxaneor the benzene-insoluble organoaluminum oxy-compound having beendisclosed in Japanese Patent L-O-P No. 276807/1990.

The above-mentioned aluminoxane may be prepared, for example, by thefollowing procedures:

(1) a procedure for recovering an aluminoxane as its hydrocarbonsolution which comprises adding an organoaluminum compound such astrialkylaluminum to a suspension in a hydrocarbon medium of a compoundcontaining adsorbed water, or a salt containing water of crystallizationsuch as magnesium chloride hydrate, copper sulfate hydrate, aluminumsulfate hydrate, nickel sulfate hydrate and cerium chloride hydrate, andreacting the organoaluminum compound;

(2) a procedure for recovering an aluminoxane as its hydrocarbonsolution which comprises reacting water, ice or steam directly with anorganoaluminum compound such as trialkylaluminum in a solvent such asbenzene, toluene, ethyl ether and tetrahydrofuran; and

(3) a procedure for recovering an aluminoxane which comprises reactingan organotinoxide such as dimethyltinoxide and dibutyltinoxide with anorganoaluminum compound such as trialkylaluminum in a solvent such asdecane, benzene or toluene.

Moreover, the aluminoxane may contain .a small amount of an organometalcomponent. Furthermore, the solvent or unreacted organoaluminum compoundmay be removed from the above-mentioned recovered aluminoxane-containingsolution, by distillation, and the aluminoxane may be redissolved in asolvent.

Concrete examples of the organoaluminum compound used for thepreparation of the aluminoxane include

trialkylaluminum such as trimethylaluminum, triethylaluminum,tripropylaluminum, triisopropylaluminum, tri-n-butylaluminum,triisobutylaluminum, tri-sec-butylaluminum, tri-tert-butylaluminum,tripentylaluminum, trihexylaluminum, trioctylaluminum andtridecylaluminum;

tricycloalkylaluminums such as tricyclohexylaluminum andtricyclooctylaluminum;

dialkylaluminum halides such as dimethylaluminum chloride,diethylaluminum chloride, diethylaluminum bromide and diisobutylaluminumchloride;

dialkylaluminum hydrides such as diethylaluminum hydride anddiisobutylaluminum hydride;

dialkylaluminum alkoxides such as dimethylaluminum methoxide anddiethylaluminum ethoxide; and

dialkylaluminum aryloxides such as diethylaluminum phenoxide.

Of these compounds, trialkylaluminum and tricycloalkylaluminum areparticularly preferable.

Furthermore, there may also be used as the organoaluminum compoundisoprenylaluminum represented by the general formula

    (i-C.sub.4 H.sub.9).sub.x Al.sub.y (C.sub.5 H.sub.10).sub.z

wherein x, y and z are each a positive number, and z≧2x.

The organoaluminum compounds mentioned above may be used either singlyor in combination.

Solvents used for the solutions of the aluminoxane include aromatichydrocarbons such as benzene, toluene, xylene, cumene and cymene;aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane,dodecane, hexadecane and octadecane; alicyclic hydrocarbons such ascyclopentane, cyclohexane, cyclooctane and methylcyclopentane; petroleumfractions such as gasoline, kerosene and gas oil; and halogenatedcompounds derived from the above-mentioned aromatic hydrocarbons,aliphatic hydrocarbons and alicyclic hydrocarbons, especiallychlorinated and brominated hydrocarbons.

In addition, there may also be used ethers such as ethyl ether andtetrahydrofuran. Of these solvents as exemplified above, aromatichydrocarbons are particularly preferred.

The benzene-insoluble organoaluminum oxy-compounds used as component (a)contain an Al component soluble in benzene at 60° C. in an amount of notgreater than 10%, preferably not greater than 5%, particularlypreferably not greater than 2% in terms of Al atom, and they areinsoluble or sparingly soluble in benzene.

Solubility in benzene of such organoaluminum oxy-compounds as mentionedabove is obtained by suspending in 100 ml of benzene the organoaluminumoxy-compound in an amount corresponding to 100 mg atoms in terms of Al,mixing the resulting suspension at 60° C. for 6 hours with stirring,filtering the resulting mixture with a G-5 glass filter equipped with ajacket kept at 60° C., washing 4 times the solid portion separated onthe filter with 50 ml of benzene at 60° C., and measuring the amount(×mmole) of Al atoms present in the whole filtrate.

The transtion metal compound catalyst component (b) hereinaftersometimes referred to as "component (b)"! used in the preparation of theethylene/α-olefin copolymers A1! and A2! is a compound of a transitionmetal in Group IVB of the periodic table which has a ligand having acyclopentadienyl skeleton. Concretely, the component (b) is a transitionmetal compound represented by the following formula b-I! or b-II!.

    ML.sup.1 .sub.x                                             b-I!

In the formula b-I!, M is a transition metal atom selected from GroupIVB of the periodic table, L¹ is a ligand coordinating to the transitionmetal atom, at least two of L¹ are groups selected from acyclopentadienyl group, a methylcyclopentadienyl group, anethylcyclopentadienyl group and a substituted cyclopentadienyl grouphaving at least one substituent group selected from a hydrocarbon groupof 3 to 10 carbon atoms, L¹ other than the (substituted)cyclopentadienyl group is a hydrocarbon group of 1 to 12 carbon atoms,an alkoxy group, an aryloxy group, a trialkylsilyl group, a halogen atomor a hydrogen atom. X is a valence of the transition metal atom M.

    ML.sup.2 .sub.x                                             b-II!

In the formula b-II!, M is a transition metal atom selected from GroupIVB of the periodic table, L² is a ligand coordinating to the transitionmetal atom, at least two of L² are substituted cyclopentadienyl groupshaving 2-5 substituent groups selected from a methyl group and an ethylgroup, and L² other than the substituted cyclopentadienyl group is ahydrocarbon group of 1 to 12 carbon atoms, an alkoxy group, an aryloxygroup, a trialkylsilyl group, a halogen atom or a hydrogen atom. X is avalence of the transition metal atom M.

The transition metal compounds represented by the above formula b-I! orb-II! are explained below in detail.

In the above formula b-I!, M is a transition metal atom selected fromGroup IVB of the periodic table, and it is concretely zirconium,titanium or hafnium, preferably zirconium.

L¹ is a ligand coordinating to the transition metal atom M, and at leasttwo of L¹ are groups selected from a cyclopentadienyl group, amethylcyclopentadienyl group, an ethylcyclopentadienyl group and asubstituted cyclopentadienyl group having at least one substituent groupselected from a hydrocarbon group of 3 to 10 carbon atoms. Each ofligands may be the same or different. L¹ other than the cyclopentadienylgroup or the substituted cyclopentadienyl group is a hydrocarbon groupof 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, atrialkylsilyl group, a halogen atom or a hydrogen atom.

The substituted cyclopentadienyl group may have two or more ofsubstituents. Each of substituents may be the same or different. Whenthe substituted cyclopentadienyl has two or more of substituents, atleast one substituent is a hydrocarbon group of 3 to 10 carbon atoms,and the other substituents are selected from a methyl group, an ethylgroup and the hydrocarbon group of 3 to 10 carbon atoms.

Examples of the hydrocarbon group of 3 to 10 carbon atoms include alkylgroup, cycloalkyl group, aryl group and aralkyl group. Concrete examplesthereof include alkyl group such as n-propyl group, isopropyl group,n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentylgroup, hexyl group, octyl group, 2-ethylhexyl group and decyl group;cycloalkyl group such as cyclopentyl group and cyclohexyl group; arylgroup such as phenyl group and tolyl group; and aralkyl group such asbenzyl group and neophyl group. Of these, preferred are alkyl groups,and particularly preferred are n-propyl group and n-butyl group.

In the present invention, the (substituted) cyclopentadienyl groupcoordinated to the transition metal is preferably the substitutedcyclopentadienyl group, more preferably the cyclopentadienyl groupsubstituted with alkyl group having 3 or more of carbon atoms, furtherpreferably the substituted cyclopentadienyl group having twosubstituents, and particularly the 1,3-substituted cyclopentadienylgroup.

In the above-mentioned formula b-I!, ligand L¹ other than thecyclopentadienyl group or the substituted cyclopentadienyl group is ahydrocarbon group of 1 to 12 carbon atoms, an alkoxy group, an aryloxygroup, a trialkylsilyl group, a halogen atom or a hydrogen atom.

Examples of the hydrocarbon group of 1 to 12 carbon atoms include alkylgroup, cycloalkyl group, aryl group and aralkyl group. Concrete examplesthereof include alkyl group such as methyl group, ethyl group, n-propylgroup, isopropyl group, n-butyl group, isobutyl group, sec-butyl group,t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexylgroup and decyl group; cycloalkyl group such as cyclopentyl group andcyclohexyl group; aryl group such as phenyl group and tolyl group; andaralkyl group such as benzyl group and neophyl group.

Examples of the alkoxy group include methoxy group, ethoxy group,n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group,sec-butoxy group, t-butoxy group, pentoxy group, hexoxy group and octoxygroup.

Examples of the aryloxy group include phenoxy group and the like.

Examples of the trialkylsilyl group include trimethylsilyl group,triethylsilyl group and triphenylsilyl group.

Examples of the halogen atom include fluorine, chlorine, bromine andiodine.

Listed below are examples of the transition metal compound representedby the formula b-I!.

Bis(cyclopentadienyl)zirconium dichloride,

Bis(methylcyclopentadienyl)zirconium dichloride,

Bis(ethylcyclopentadienyl)zirconium dichloride,

Bis(n-propylcyclopentadienyl)zirconium dichloride,

Bis(n-butylcyclopentadienyl)zirconium dichloride,

Bis(n-hexylcyclopentadienyl)zirconium dichloride,

Bis(methyl-n-propylcyclopentadienyl)zirconium dichloride,

Bis(methyl-n-butylcyclopentadienyl)zirconium dichloride,

Bis(dimethyl-n-butylcyclopentadienyl)zirconium dichloride,

Bis(n-butylcyclopentadienyl)zirconium dibromide,

Bis(n-butylcyclopentadienyl)zirconium methoxychloride,

Bis(n-butylcyclopentadienyl)zirconium ethoxychloride,

Bis(n-butylcyclopentadienyl)zirconium butoxychloride,

Bis(n-butylcyclopentadienyl)zirconium diethoxide,

Bis(n-butylcyclopentadienyl)zirconium methylchloride

Bis(n-butylcyclopentadienyl)zirconium dimethyl,

Bis(n-butylcyclopentadienyl)zirconium benzylchloride,

Bis (n-butylcyclopentadienyl)zirconium dibenzyl,

Bis (n-butylcyclopentadienyl)zirconium phenylchloride, and

Bis(n-butylcyclopentadienyl)zirconium hydride chloride.

In the above exemplified compounds, di-substituted cyclopentadienylinclude 1,2- and 1,3-substituted, and tri-substituted include 1,2,3- and1,2,4-substituted. Also employable in the invention are transition metalcompounds obtained by substituting titanium metal or hafnium metal forthe zirconium metal in the above-exemplified zirconium compounds.

Of the above-exemplified transition metal compounds represented by theformula b-I!, particularly preferred areBis(n-propylcyclopentadienyl)zirconium dichloride,Bis(n-butylcyclopentadienyl)zirconium dichloride,Bis(1-methyl-3-n-propylcyclopentadienyl)zirconium dichloride andBis(1-methyl-3-n-butylcyclopentadienyl)zirconium dichloride.

In the above-mentioned formula b-II!, M is a transition metal selectedfrom Group IVB of the periodic table, and concrete preferable examplesof M include zirconium, titanium and hafnium. Of these, particularlypreferred is zirconium.

L² is a ligand coordinated to the transition metal, and at least two ofthem are substituted cyclopentadienyl groups having 2-5 of substituentsselected from a methyl group and an ethyl group. Each of ligands may bethe same or different. The substituted cyclopentadienyl groups are thesubstituted cyclopentadienyl groups having 2 or more of substituents,preferably the substituted cyclopentadienyl groups having 2 or 3 ofsubstituents, more preferably the substituted cyclopentadienyl groupshaving two substituents, particularly the 1,3-substitutedcyclopentadienyl groups. Each of substituents may be the same ordifferent.

In the above-mentioned formula b-II!, ligand L² other than thesubstituted cyclopentadienyl group is a hydrocarbon group of 1 to 12carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group,a halogen atom or a hydrogen atom as similar to the ligand L¹ in theabove-mentioned formula b-I!.

The transition metal compound represented by the general formula b-II!include, for example,

Bis(dimethylcyclopentadienyl)zirconium dichloride,

Bis(diethylcyclopentadienyl)zirconium dichloride,

Bis(methylethylcyclopentadienyl)zirconium dichloride,

Bis(dimethylethylcyclopentatienyl)zirconium dichloride,

Bis(dimethylcyclopentadienyl)zirconium dibromide,

Bis(dimethylcyclopentadienyl)zirconium methoxychloride,

Bis(dimethylcyclopentadienyl)zirconium ethoxychloride,

Bis(dimethylcyclopentadienyl)zirconium butoxychloride,

Bis(dimethylcyclopentadienyl)zirconium diethoxide,

Bis(dimethylcyclopentadienyl)zirconium methylchloride,

Bis(dimethylcyclopentadienyl)zirconium dimethyl,

Bis(dimethylcyclopentadienyl)zirconium benzylchloride,

Bis(dimethylcyclopentadienyl)zirconium dibenzyl,

Bis(dimethylcyclopentadienyl)zirconium phenylchloride,

and Bis(dimethylcyclopentadienyl)zirconium hydride chloride.

In the above exemplified compounds, di-substituted cyclopentadienylinclude 1,2- and 1,3-substituted, and tri-substituted include 1,2,3- and1,2,4-substituted.

There may also be used transition metal compounds obtained bysubstituting titanium or hafnium for zirconium in the above-exemplifiedzirconium compounds.

In the above-mentioned transition metal compounds represented by thegeneral formula b-II!, particularly preferred is

Bis(1,3-dimethylcyclopentadienyl)zirconium dichloride,

Bis(1,3-diethylcyclopentadienyl)zirconium dichloride, or

Bis(1-methyl-3-ethylcyclopentadienyl)zirconium dichloride.

In the invention, it is preferred to use a combination of at least onekind of a transition metal compound represented by the above formulab-I! and at least one kind of a transition metal compound represented bythe above formula b-II! as the transition metal compound (b).

In concrete, preferably used are a combination ofbis(1,3-n-butylmethylcyclopentadienyl)zirconium dichloride andbis(1,3-dimethylcyclopentadienyl)zirconium dichloride, a combination ofbis(1,3-n-propylmethylcyclopentadienyl)zirconium dichloride andbis(1,3-dimethylcyclopentadienyl)zirconium dichloride, and a combinationof bis(n-butylcyclopentadienyl) zirconium dichloride andbis(1,3-dimethylcyclopentadienyl)zirconium dichloride.

The above-mentioned at least-one kind of a transition metal compound(b-I) represented by the formula b-I! and at least one kind of atransition metal compound (b-II) represented by the formula b-II! aredesirably used in such amounts that the molar ratio (b-I)/(b-II)! is inthe range of 99/1 to 50/50, preferably 97/3 to 70/30, more preferably95/5 to 75/25, most preferably 90/10 to 80/20.

A transition metal compound catalyst component containing at least onekind of a transition metal compound (b-I) represented by the formulab-I! and at least one kind of a transition metal compound (b-II)represented by the formula b-II! is sometimes referred to as "component(b)" hereinafter.

The compound (b') (hereinafter called "component (b')" in some cases) ofthe IVB group transition metal of the periodic table which contains aligand having a cyclopentadienyl skeleton used in the preparation theethylene/α-olefin copolymer B1! in the invention is no way limited asfar as it is a compound of a transition metal in Group IV of theperiodic table which contains a ligand having a cyclopentadienylskeleton. However, the component (b') is preferably a transitioncompound represented by the following formula b-III!.

    ML.sub.x                                                    b-III!

wherein M is a transition metal atom selected from Group IVB of theperiodic table, L is a ligand coordinating to the transition metal, atleast one of L is a ligand having a cyclopentadienyl skeleton, and Lother than the ligand having a cyclopentadienyl skeleton is ahydrocarbon group of 1-12 carbon atoms, an alkoxy group, an aryloxygroup, an aryloxy group, a trialkylsilyl group, SO₃ R group (providedthat R is a hydrocarbon group which may have such a substituent ashalogen), halogen atom or hydrogen atom, and x is a valence of thetransition metal atom.

The transition metal compound represented by the above formula b-III!include the transition metal compound (b-I) represented by the aboveformula b-I! and the transition metal compound (b-II) represented by theabove formula b-II!.

In the above-mentioned formula b-III!, M is a transition metal selectedfrom Group IVB of the periodic table, and concrete preferable examplesof M include zirconium, titanium and hafnium. Of these, particularlypreferred is zirconium.

The ligands having a cyclopentadienyl skeleton are, for example,cyclopentadienyl group, alkyl-substituted cyclopentadienyl groups suchas methylcyclopentadienyl, dimethylcyclopentadienyl,trimethylcyclopentadienyl, tetramethylcyclopentadienyl,pentamethylcyclopentadienyl, ethylcyclopentadienyl,methylethylcyclopentadienyl, propylcyclopentadienyl,methylpropylcyclopentadienyl, butylcyclopentadienyl,methylbutylcyclopentadienyl and hexylpentadienyl, or indenyl group,4,5,6,7-tetrahydroindenyl group and fluorenyl group. These groups asexemplified above may be substituted with a halogen atom ortrialkylsilyl group.

Of the ligands coordinating with the transition metal atom, particularlypreferred is an alkyl-substituted cyclopentadienyl group.

When the compound represented by the general formula b-III! contains 2or more ligands each having a cyclopentadienyl skeleton, the two ligandsout of those having a cyclopentadienyl skeleton may be linked togetherthrough an alkylene group such as ethylene or propylene, a substitutedalkylene group such as isopropylidene or diphenylmethylene, a silylenegroup or a substituted silylene group such as dimethylsilylene,diphenylsilylene or methylphenylsilylene.

The ligands L other than those having a cyclopentadienyl skeleton mayinclude those mentioned below.

The hydrocarbon group of 1-12 carbon atoms includes such group as alkyl,cycloalkyl, aryl or aralkyl, and more particularly, the alkyl groupincludes methyl, ethyl, propyl, isopropyl or butyl; the cycloalkyl groupincludes cyclopentlyl or cyclohexyl; the aryl group includes phenyl ortolyl; and the aralkyl group includes benzyl or neophyl.

Further, the alkoxy group includes methoxy, ethoxy or butoxy; aryloxygroup includes phenoxy; the ligand represented by SO₃ 3 ^(R) includesp-toluenesulfonate, methanesulfonate or trifluoromethanesulfonate; andthe halogen includes fluorine, chlorine, bromine or iodine.

When the valence of the transition metal atom is, for example, 4, thetransition metal compound (b') containing ligands having acyclopentadienyl skeleton is represented by the following formulab-III'! in more detail.

    R.sup.2.sub.k R.sup.3.sub.l R.sup.4.sub.m R.sup.5.sub.n M   b-III'!

wherein M represents the same transition metal atom as in the formulab-III!, R² represents a group (ligand) having a cyclopentadienylskeleton, R³, R⁴ and R⁵ each represent a group having a cyclopentadienylskeleton, alkyl group, cycloalkyl group, aryl group, aralkyl group,alkoxyl group, aryloxy group, trialkylsilyl group, SO₃ R group, halogenatom or hydrogen atom, k is an integer of 1 or more, and k+l+m+n=4.

In the present invention, there is used preferably a metallocenecompound having the above-mentioned formula b-III'! in which at leasttwo of R², R³, R⁴ and R⁵ are the groups (ligands) having acyclopentadienyl skeleton, for example, R² and R³ are the groups(ligands) having a cyclopentadienyl.

The groups having a cyclopentadienyl skeleton mentioned above may belinked together through an alkylene group such as ethylene or propylene,a substituted alkylene group such as isopropylene or diphenylmethylene,a silylene group or a substituted silylene group such asdimethylsilylene, diphenylsilylene or methylphenylsilylene.

Further, R⁴ and R⁵ in the above-mentioned formula b-III'! are each agroup having a cyclopentadienyl skeleton, alkyl group, cycloalkyl group,aryl group, arlakyl group, alkoxyl group, aryloxy group, trialkylsilylgroup, SO₃ R group, halogen atom or hydrogen atom.

Exemplified below are the transition metal compounds (b') of the formulab-III'! wherein M is zirconium.

Bis(indenyl)zirconium dichloride,

Bis(indenyl)zirconium dibromide,

Bis(indenyul)zirconium bis(p-toluenesulfonate),

Bis(4,5,6,7-tetrahydroindenyl)zirconium dichloride,

Bis(fluorenyl)zirconium dichloride,

Ethylenebis(indenyl)zirconium dichloride,

Ethylenebis(indenyl)zirconium dibromide,

Ethylenebis(indenyl)dimethylzirconium,

Ethylenebis(indenyl)diphenylzirconium,

Ethylenebis(indenyl)methylzirconium monochloride,

Ethylenebis(indenyl)zirconium bis(methanesulfonate),

Ethylenebis(indenyl)zirconium bis(p-toluenesulfonate),

Ethylenebis(indenyl)zirconium bis(trifluoromethanesulfonate),

Ethylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride,

Isopropylidene(cyclopentadienyl-fluorenyl)zirconium dichloride,

Isopropylidene(cyclopentadienyl-methylcyclopentadienyl)zirconiumdichloride,

Dimethylsilylenebis(cyclopentadienyl)zirconium dichloride,

Dimethylsilylenebis(methylcyclopentadienyl)zirconium dichloride,

Dimethylsilylenebis(dimethylcyclopentadienyl)zirconium dichloride,

Dimethylsilylenebis(trimethylcyclopentadienyl) zirconium dichloride,

Dimethylsilylenebis(indenyl)zirconium dichloride,

Dimethylsilylenebis(indenyl)zirconium bis(trifluoromethane-sulfonate),

Dimethylsilylenebis(4,5,6,7-tetrahydroindenyl) zirconium dichloride,

Dimethylsilylene(cyclopentadienyl-fluorenyl)zirconium dichloride,

Diphenylsilylenebis(indenyl)zirconium dichloride,

Methylphenylsilylenebis(indenyl)zirconium dichloride,

Bis(cyclopentadienyl)zirconium dichloride,

Bis(cyclopentadienyl)zirconium dibromide,

Bis(cyclopentadienyl)methylzirconium monochloride,

Bis(cyclopentadienyl)ethylzirconium monochloride,

Bis(cyclopentadienyl)cyclohexylzirconium monochloride,

Bis(cyclopentadienyl)phenylzirconium monochloride,

Bis(cyclopentadienyl)benzylzirconium monochloride,

Bis(cyclopentadienyl)zirconium monochloride monohydride,

Bis(cyclopentadienyl)methylzirconium monohydride,

Bis(cyclopentadienyl)dimethylzirconium,

Bis(cyclopentadienyl)diphenylzirconium,

Bis(cyclopentadienyl)dibenzylzirconium,

Bis(cyclopentadienyl)zirconium methoxychloride,

Bis(cyclopentadienyl)zirconium ethoxychloride,

Bis(cyclopentadienyl)zirconium bis(methanesulfonate),

Bis(cyclopentadienyl)zirconium bis(p-toluenesulfonate),

Bis(cyclopentadienyl)zirconium bis(trifluoromethanesulfonate),

Bis(methylcyclopentadienyl)zirconium dichloride,

Bis(dimethylcyclopentadienyl)zirconium dichloride,

Bis(dimethylcyclopentadienyl)zirconium ethoxychloride,

Bis(dimethylcyclopentadienyl)zirconium bis(trifluoromethanesulfonate),

Bis(ethylcylopentadienyl)zirconium dichloride,

Bis(methylethylcyclopentadienyl)zirconium dichloride,

Bis(propylcyclopentadienyl)zirconium dichloride,

Bis(methylpropylcyclopentadienyl)zirconium dichloride,

Bis(butylcylcopentadienyl)zirconium dichloride,

Bis(methylbutylcyclopentadienyl)zirconium dichloride,

Bis(methylbutylcyclopentadienyl)zirconium bis(methanesulfonate),

Bis(trimethylcyclopentadienyl)zirconium dichloride,

Bis(tetramethylcyclopentadienyl)zirconium dichloride,

Bis(pentamethylcyclopentadienyl)zirconium dichloride,

Bis(hexylcyclopentadienyl)zirconium dichloride, and

Bis(trimethylsilylcyclopetnadienyl)zirconium dichloride.

In the compounds exemplified above, the di-substituted cyclopentadienylring includes 1,2- and 1,3-substituted compounds, and thetri-substituted cyclopentadienyl ring includes 1,2,3- and1,2,4-substituted compounds. Further, the alkyl group such as propyl orbutyl includes isomer such as n-, i-, sec-, tert-compounds.

In the present invention, the above-exemplified zirconium compounds inwhich the zirconium has been replaced by titanium or hafnium can also beused as the transition metal compounds.

The carrier used in the preparation of the ethylene/α-olefin copolymersA1!, A2! and B1! in present invention is a solid inorganic or organiccompound in granules or fine particles having a particle size of 10 to300 μm, preferably 20 to 200 μm. Of these carriers, porous oxides arepreferable as inorganic carriers. Concrete examples of the oxidecarriers include SiO₂, Al₂ O₃, MgO, ZrO₂, TiO₂, B₂ O₃, CaO, ZnO, BaO,ThO₂, or a mixture of these compounds such as SiO₂ --MgO, SiO₂ --Al₂ O₃,SiO₂ --TiO₂ l , SiO₂ --V₂ O₅, SiO₂ --Cr₂ O₃ and SiO₂ --TiO₂ --MgO. Ofthese carriers, preferred are those comprising at least one compoundselected from the group consisting of SiO₂ and Al₂ O₃ as a majorcomponent.

Furthermore, the above-mentioned inorganic oxide or oxides may alsocontain a small amount of a carbonate, a sulfate, a nitrate and an oxidesuch as Na₂ CO₃, K₂ CO₃, CaCO₃, MgCO₃, Na₂ SO₄, Al₂ (SO₄)₃, BaSO₄, KNO₃,Mg(NO₃)₂, Al(NO₃)₃, Na₂ O, K₂ O and LiO₂.

Though the carriers have different properties among them depending onthe types and preparation methods thereof, the carriers preferably usedin the invention have a specific surface area of 50 to 1000 m² /g,preferably 100 to 700 m² /g, a pore volume of desirably 0.3 to 2.5 cm²/g. The carriers are prepared if necessary by firing at a temperature of100° to 1000° C., preferably 150° to 700° C.

It is also desirable that this carrier has an amount of adsorbed waterof less than 1.0% by weight, preferably less than 0.5% by weight, and asurface hydroxyl group in an amount of 1.0% by weight or more,preferably 1.5-4.0% by weight and especially 2.0-3.5% by weight.

The amount of adsorbed water (% by weight) and that of the surfacehydroxyl group (% by weight) are obtained by the following procedures.

(Amount of adsorbed water)

The specimen is dried at a temperature of 200° C., an ordinary pressureand in a nitrogen stream for 4 hours to measure a weight loss which isthen taken as the amount of adsorbed water.

(Surface hydroxyl group)

The weight measured by drying the carrier at a temperature of 200° C.,an ordinary pressure in a nitrogen stream for 4 hours is taken as X (g),and the carrier as dried is then calcined at a temperature of 1,000° C.for 20 hours to obtain a calcined product from which the surfacehydroxyl groups have disappeared, and the weight of the calcinationproduct as measured is taken as Y (g). The amount of the surfacehydroxyl groups is calculated on the basis of the following equation.

Surface hydroxyl group (wt %)= (X-Y)/X!×100

Moreover, there can be mentioned organic compounds in solid granules orfine solid particles each having a particle size of 10 to 300 μm ascarriers which can be used as the carrier in the present invention.Examples of these organic compounds include (co)polymers containing asthe main component constituent units derived from an α-olefin of 2 to 14carbon atoms, such as ethylene, propylene, 1-butene and4-methyl-1-pentene, or polymers or copolymers containing as the maincomponent constituent units derived from vinylcyclohexane or styrene.

Though the catalyst for preparing the ethylene/α-olefin copolymers A1!and A2! is formed from the organoaluminum oxy-compound (a), at least twokinds of the transition metal compounds (b) and the carrier, and thecatalyst for preparing the ethylene/α-olefin copolymer B1! is formedfrom the organoaluminum oxy-compound (a), the transition metal compound(b') and the carrier, each catalyst may, if necessary, contain anorganoaluminum compound (c).

Examples of the organoaluminum compound (c) hereinafter sometimesreferred to as "component (c)"! include an organoaluminum compoundrepresented by the following formula IV!.

    R.sup.1.sub.n AlX.sub.3-n                                   IV!

wherein R¹ is a hydrocarbon group of 1 to 12 carbon atoms, X is ahalogen atom or a hydrogen atom, and n is 1 to 3.

In the above formula IV!, R¹ is a hydrocarbon group of 1 to 12 carbonatoms, for example, an alkyl group, a cycloalkyl group or an aryl group.Concrete examples of R¹ include methyl, ethyl, n-propyl, isopropyl,isobutyl, pentyl, hexyl, octyl, cyclopentyl, cyclohexyl, phenyl andtolyl.

Concrete examples of such organoaluminum compounds (c) include

trialkylaluminum such as trimethylaluminum, triethylaluminum,triisopropylaluminum, triisobutylaluminum, trioctylaluminum andtri-2-ethylhexylaluminum;

alkenylaluminum such as isoprenylaluminum;

dialkylaluminum halides such as dimethylaluminum chloride,diethylaluminum chloride, diisopropylaluminum chloride,diisobutylaluminum chloride and dimethylaluminum bromide;

alkylaluminum sesquihalides such as methylaluminum sesquichloride,ethylaluminum sesquichloride, isopropylaluminum sesquichloride,butylaluminum sesquichloride and ethylaluminum sesquibromide;

alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminumdichloride, isopropylaluminum dichloride and ethylaluminum dibromide;and

alkylaluminum hydrides such as diethylaluminum hydride anddiisobutylaluminum hydride.

Furthermore, there may also be used other organoaluminum compoundsrepresented by the following formula V! as the organoaluminum compoundcatalyst component (c);

    R.sup.1.sub.n AlY.sub.3-n                                   V!

wherein R^(i) is as defined previously, Y is --OR², --OSiR³, --OAlR⁴ ₂,--NR⁵ ₂, --SiR⁶ ₃ or --N(R⁷)AlR⁸ ₂, n is 1 to 2, R², R³, R⁴ and R⁸ areeach methyl, ethyl, isopropyl, isobutyl, cyclohexyl or phenyl, R⁵ ishydrogen, methyl, ethyl, isopropyl, phenyl or trimethylsilyl, R⁶ and R⁷are each methyl or ethyl.

The organoaluminum compounds as mentioned above include, in concrete,such compounds as enumerated below.

(1) Compounds of the formula R¹ _(n) Al(OR²)_(3-n) such asdimethylaluminum methoxide, diethylalumlnum ethoxide anddiisobutylaluminum methoxide.

(2) Compounds of the formula R¹ _(n) Al(OSiR³ ₃)_(3-n) such as Et₂Al(OSiMe₃), (iso-Bu)₂ Al(OSiMe₃) and (iso-Bu)₂ Al(OSiEt₃).

(3) Compounds of the formula R¹ _(n) Al(OAlR⁴ ₂)_(3-n) such as Et₂AlOAEt₂ and (iso-Bu)₂ AlOAl(iso-Bu)₂.

(4) Compounds of the formula R¹ _(n) Al(NR⁵ ₂)_(3-n) such as Me₂ AlNEt₂,Et₂ AlNHMe, Me₂ AlNHEt, Et₂ AlN(SiMe₃)₂, (iso-Bu)₂ AlN(SiMe₃)₂.

(5) Compounds of the formula R¹ _(n) Al(SiR⁶ ₃)_(3-n) such as (iso-Bu)₂AlSiMe₃.

(6) Compounds of the formula ##STR1## such as ##STR2## and ##STR3##

Of the organoaluminum compounds as exemplified above, preferred arethose having the formulas

    R.sup.1.sub.3 Al, R.sup.1.sub.n Al(OR.sup.2).sub.3-n

and

    R.sup.1.sub.n Al(OAlR.sup.4.sub.2).sub.3-n,

and particularly preferred are those having the above-mentioned formulasin which R is isoalkyl and n is 2.

In the preparation of the ethylene/α-olefin copolymers A1! and A2!, asolid catalyst (1) prepared by contacting the component (a), thecomponent (b) and the carrier, and if necessary the component (c), ispreferably used. The contact between the components (a) to (c) and thecarrier may be conducted in an arbitrarily selected order, butpreferably the carrier is first contacted with the component (a), thenwith the component (b) and if necessary with the component (c). Further,it is preferred that at least two kinds of the transition metalcompounds are beforehand mixed to form the component (b) and then thecomponent (b) is contacted with other components.

The contact between the components (a) to (c) and the carrier can becarried out in an inert hydrocarbon solvent. Concrete examples of theinert hydrocarbon solvent used for preparing the catalyst includealiphatic hydrocarbons, such as propane, butane, pentane, hexane,heptane, octane, decane, dodecane and kerosine; alicyclic hydrocarbons,such as cyclopentane, cyclohexane and methylcyclopentane; aromatichydrocarbons, such as benzene, toluene and xylene; halogenatedhydrocarbons, such as ethylene chloride, chlorobenzene anddichloromethane; and mixtures thereof.

When the component (a), the component (b) and the carrier, and ifnecessary, the component (c) are mixed and contacted, the component (b)is used in an amount of usually 5×10⁻⁶ to 5×10⁻⁴ mol, preferably 10⁻⁵ to2×10⁻⁴ mol, per 1 g of the carrier, and the concentration of thecomponent (b) is in the range of about 10⁻⁴ to 2×10⁻² mol/l (solvent),preferably 2×10³¹ 4 to 10⁻² mol/l (solvent). An atomic ratio(Al/transition metal) of the aluminum atom (Al) in the component (a) tothe transition metal in the component (b) is in the range of usually 10to 500, preferably 20 to 200. An atomic ratio (Al-c/Al-a) of thealuminum atom (Al-c) in the component (c) which is optionally used tothe aluminum atom (Al-a) in the component (a) is in the range of usually0.02 to 3, preferably 0.05 to 1.5. The temperature for contacting thecomponent (a), the component (b) and the carrier, and if necessary thecomponent (c), is in the range of usually -50° to 150° C., preferably-20° to 120 ° C., and the period of time therefor is in the range of 1minute to 50 hours, preferably 10 minutes to 25 hours.

In the preparation of the ethylene/α-olefin copolymer B1!, a solidcatalyst (2) prepared by contacting the component (a), the component(b') and the carrier, and if necessary the component (c), is preferablyused. The solid catalyst can be prepared in a manner similar to that forthe solid catalyst (1) used for preparing the above-mentionedethylene/α-olefin copolymers A1! and A2!.

In the solid catalyst (1) used for the preparation of theethylene/α-olefin copolymers A1! and A2! or in the the solid catalyst(2) used for the preparation of the ethylene/α-olefin copolymer B1!, thetransition metal atom derived from the component (b) (or the component(b')) is desirably supported in an amount of 5×10⁻⁶ to 5×10⁻⁴ g.atom,preferably 10³¹ 5 to 2×10⁻⁴ g.atom, per 1 g of the carrier, and thealuminum atom derived from the component (a) and the component (c) isdesirably supported in an amount of 10⁻³ to 5×10⁻² g.atom, preferably2×10⁻³ to 2×10⁻² g.atom, per 1 g of the carrier.

The catalyst for olefin polymerization used for the preparation of theethylene/α-olefin copolymers A1! and A2! may be a prepolymerizedcatalyst obtained by prepolymerizing an olefin in the presence of thecomponent (a), the component (b), the carrier and if necessary thecomponent (c). The prepolymerization can be carried out by introducingan olefin into an inert hydrocarbon solvent in the presence of thecomponent (a), the component (b), the carrier and if necessary thecomponent (c), or in the presence of the solid catalyst component (1)prepared by contacting the component (a), the component (b), thecomponent (c) and if necessary the component (c).

Examples of the olefins employable for the prepolymerization includeethylene, and α-olefins having 3 to 20 carbon atoms such as propylene,1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene,1-dodecene and 1-tetradecene. Of these, particularly preferred isethylene or a combination of ethylene and the same α-olefin as used forthe polymerization.

In the prepolymerization, the component (b) is used in an amount ofusually 10⁻⁶ to 2×10⁻² mol/l (solvent), preferably 5×10⁻⁵ to 10⁻² mol/l(solvent). Further, the component (b) is used in an amount of usually5×10⁻⁶ to 5×10⁻⁴ mol, preferably 10⁻⁵ to 2×10⁻⁴ mol, per 1 g of thecarrier. An atomic ratio (Al/transition metal) of the aluminum atom (Al)in the component (a) to the transition metal in the component (b) is inthe range of usually 10 to 500, preferably 20 to 200. An atomic ratio(Al-c/Al-a) of the aluminum atom (Al-c) in the component (c) which isoptionally used to the aluminum atom (Al-a) in the component (a) is inthe range of usually 0.02 to 3, preferably 0.05 to 1.5.

The solid catalyst component (1) is used in an amount of usually 10⁻⁶ to2×10⁻² mol/l (solvent), preferably 5×10⁻⁵ to 10⁻² mol/l (solvent), interms of the transition metal atom derived from the transition metalcompound in the solid catalyst component.

The temperature for the prepolymerization is in the range of -20° to 80°C., preferably 0° to 60° C., and the period of time therefor is in therange of 0.5 to 100 hours, preferably 1 to 50 hours.

The prepolymerization may be carried out either batchwise orcontinuously, and may be carried out under reduced pressure, atmosphericpressure or application of pressure. In the prepolymerization, hydrogenis desirably allowed to exist to obtain a prepolymer having an intrinsicviscosity η!, as measured in decalin at 135° C., of 0.2 to 7 dl/g,preferably 0.5 to 5 dl/g.

It is desired that an olefin polymer is prepared by theprepolymerization in an amount of 0.1 to 500 g, preferably 0.2 to 300 g,more preferably 0.5 to 200 g, per 1 g of the carrier.

The prepolymerized catalyst (1) can be prepared, for example, in thefollowing manner. First, the carrier is suspended in an inerthydrocarbon to give a suspension. To the suspension is added theorganoaluminum oxy-compound (component (a)) to perform reaction for apredetermined time. Then, a supernatant liquid is removed, and theresultant solid component is again suspended in an inert hydrocarbon.Subsequently, to the system are added the transition metal compound(component (b)) to perform reaction for a predetermined time. Asupernatant liquid is removed again to obtain a solid catalystcomponent. The solid catalyst component thus obtained is added to aninert hydrocarbon containing the organoaluminum compound (component(c)), followed by introducing an olefin, to obtain the prepolymerizedcatalyst.

The catalyst for olefin polymerization used for preparing theethylene/α-olefin copolymer B1! may be a prepolymerized catalyst (2)obtained by prepolymerizing an olefin in the presence of the component(a), the component (b'), the carrier and if necessary the component (c).

Similarly to the above-mentioned prepolymerized catalyst (1), theprepolymerized catalyst (2) can be prepared by introducing an olefininto an inert hydrocarbon solvent in the presence of the component (a),the component (b'), the carrier and if necessary the component (c), orin the presence of a solid catalyst component (2) prepared by contactingthe component (a), the component (b), the component (c) and if necessarythe component (c).

In the prepolymerized catalyst (1) (or the prepolymerized catalyst (2)),it is desired that the component (b) (or the component (b')) issupported in an amount of about 5×10⁻⁶ to 5×10⁻⁴ g.atom, preferably 10⁻⁵to 2×10⁻⁴ g.atom, in terms of the transition metal atom, per 1 g of thecarrier; and the aluminum atom (Al) derived from the component (a) andthe component (c) is supported in such an amount that the molar ratio(Al/M) of the aluminum atom (Al) derived from the component (a) and thecomponent (c) to the transition metal atom (M) derived from thecomponent (b) (or the component (b')) is in the range of 5 to 200,preferably 10 to 150.

The ethylene/α-olefin copolymers A1! and A2! for forming the ethylenecopolymer composition of the invention can be obtained by copolymerizingethylene with an α-olefin of 3 to 20 carbon atoms such as propylene,1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene,1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene, inthe presence of, for example, the aforesaid catalyst for olefinpolymerization comprising the component (a), the component (b) and thecarrier.

The ethylene/α-olefin copolymer B1! can be obtained by copolymerizingethylene with such an α-olefin of 3 to 20 carbon atoms as mentionedabove, in the presence of, for example, the aforesaid catalyst forolefin polymerization comprising the component (a), the component (b')and the carrier.

In the invention, the copolymerization of ethylene with the α-olefin iscarried out either in a gas phase or in a liquid phase such as slurry.In the slurry polymerization, an inert hydrocarbon may be used as asolvent, or the olefin itself may be used as a solvent.

Examples of the inert hydrocarbon solvent used for the slurrypolymerization include aliphatic hydrocarbons, such as propane, butane,isobutane, pentane, hexane, octane, decane, dodecane, hexadecane andoctadecane; alicyclic hydrocarbons, such as cyclopentane,methylcyclopentane, cyclohexane and cyclooctane; aromatic hydrocarbons,such as benzene, toluene and xylene; and petroleum fractions, such asgasoline, kerosine and gas oil. Of these, preferred are aliphatichydrocarbons, alicyclic hydrocarbons and petroleum fractions.

In the slurry polymerization or the gas phase polymerization, theabove-described catalyst is used in such an amount that theconcentration of the transition metal atom in the polymerizationreaction system is in the range of usually 10⁻⁸ to 10⁻³ g.atom/l,preferably 10⁻⁷ to 10⁻⁴ g.atom/l.

In the polymerization, an organoaluminum oxy-compound which is the sameas the component (a) and/or the organoaluminum compound (c) may beadded. In this case, the atomic ratio (Al/M) of the aluminum atom (Al)derived from the organoaluminum oxy-compound and the organoaluminumcompound to the transition metal atom (M) derived from the transitionmetal compound (b) (or the transition metal compound (b')) is in therange of 5 to 300, preferably 10 to 200, more preferably 15 to 150.

In the invention, the temperature for the slurry polymerization is inthe range of usually -50° to 100° preferably 0° to 90 ° C., while thetemperature for the gas phase polymerization is in the range of usually0° to 120° C. preferably 20° to 100° C.

The polymerization pressure is in the range of usually atmosphericpressure to 100 kg/cm², preferably 2 to 50 kg/cm². The polymerizationmay be carried out batchwise, semi-continuously or continuously.

Ethylene/α-olefin copolymer composition!

The first ethylene/α-olefin copolymer composition according to theinvention comprises the ethylene/α-olefin copolymer A1! and theethylene/α-olefin copolymer B1!. In this composition, it is desired thatthe ethylene/α-olefin copolymer A1! is contained in an amount of 20 to90 by weight, preferably 40 to 75% by weight, and the ethylene/α-olefincopolymer B1! is contained in an amount of 10 to 80% by weight,preferably 25 to 60% by weight. The ethylene/α-olefin copolymer A1! andthe ethylene/α-olefin copolymer B1! are different from each other.

The ethylene/α-olefin copolymers A1! and B1! are used in an appropriatecombination so that the ratio ( A1!/ B1!) in the density of theethylene/α-olefin copolymer A1! to the ethylene/α-olefin copolymer B1!is preferably less than 1, more preferably in the range of 0.930 to0.999.

The second ethylene/α-olefin copolymer composition according to theinvention comprises the ethylene/α-olefin copolymer A2! and theethylene/α-olefin copolymer B1!. In this composition, it is desired thatthe ethylene/α-olefin copolymer A2! is contained in an amount of 20 to90 by weight, preferably 40 to 75% by weight, and the ethylene/α-olefincopolymer B1! is contained in an amount of 10 to 80% by weight,preferably 25 to 60% by weight.

The ethylene/α-olefin copolymer A2! and the ethylene/α-olefin copolymerB1! are different from each other.

The ethylene/α-olefin copolymers A2! and B1! are used in an appropriatecombination so that the ratio ( A2!/ B1!) in the density of theethylene/α-olefin copolymer A2! to the ethylene/α-olefin copolymer B1!is preferably less than 1, more preferably in the range of 0.930 to0.999.

The ethylene/α-olefin copolymer composition preferably has the followingproperties (ii) to (vii).

(ii) The density (d) is in the range of usually 0.850 to 0.980 g/cm³,preferably 0.890 to 0.955 g/cm³, more preferably 0.900 to 0.950 g/cm³.

(iii) The melt flow rate (MFR) under the conditions of a temperature of190° C. and a load of 2.16 kg is in the range of usually 0.1 to 100 g/10min, preferably 0.2 to 50 g/10 min.

(iv) The melt tension (MT (g)) at 190° C. and the melt flow rate (MFR)satisfy the relation:

    MT≧2.2×MFR.sup.-0.84.

(v) The flow index (FI (l/sec)) defined by a shear rate which is givenwhen a shear stress at 190° C. reaches 2.4×10⁶ dyne/cm² and the meltflow rate (MFR) satisfy the relation:

    FI>100×MFR,

preferably

    FI>130×MFR,

more preferably

    FI>150×MFR.

(vi) The temperature (Tm (° C)) at which the endothermic curve of thecomposition measured by a differential scanning calorimeter (DSC) showsthe maximum peak and the density (d) satisfy the relation:

    Tm<400×d-250,

preferably

    Tm<450×d-297,

more preferably

    Tm<500×d-344,

particularly preferably

    Tm<550×d-391.

(vii) The quantity fraction (W (% by weight)) of a n-decane-solublecomponent at room temperature (23° C.) and the density (d) satisfy therelation:

in the case of MFR≦10 g/10 min:

    W<80×exp(-100(d-0.88))+0.1,

preferably

    W<60×exp (-100 (d-0.88))+0.1,

more preferably

    W<40×exp(-100(d-0.88))+0.1,

and

in the case of

    MFR>10 g/10 min:

    W<80×(MFR-9).sup.0.26 ×exp(-100(d-0.88))+0.1.

The ethylene/α-olefin copolymer composition according to the inventionmay contain various additives if desired, for example, weatheringstabilizer, heat stabilizer, antistatic agent, anti-slip agent,anti-blocking agent, anti-fogging agent, lubricant, pigment, dye,nucleating agent, plasticizer, anti-aging agent, hydrochloric acidabsorbent and antioxidant, provided that the object of the invention isnot marred.

The ethylene copolymer composition according to the present inventioncan be prepared by known processes, for example, processes describedbelow.

(1) A process of mechanically blending the ethylene/α-olefin copolymerA1! (or A2!), the ethylene/α-olefin copolymer B1!, and if necessary,other optional components using an extruder, a kneader or the like.

(2) A process comprising dissolving the ethylene/α-olefin copolymer A1!(or A2!), the ethylene/α-olefin copolymer B1!, and if necessary, otheroptional components in an appropriate good solvent (e.g., hydrocarbonsolvent such as hexane, heptane, decane, cyclohexane, benzene, tolueneand xylene) and, then removing the solvent from the resulting solution.

(3) A process comprising independently dissolving the ethylene/α-olefincopolymer A1! (or A2!), the ethylene/α-olefin copolymer B1!, and ifnecessary, other optional components in an appropriate good solvent toprepare solutions, then mixing the solutions, and removing the solventfrom the resulting mixture.

(4) A process in any combination of the above processes (1) to (3).

Further, the ethylene/α-olefin copolymer composition according to thepresent invention may be prepared by forming the ethylene/α-olefincopolymer A1! (or A2!) and the ethylene/α-olefin copolymer B1! in two ormore copolymerization stages having reaction conditions different fromeach other, or may be prepared by separately froming theethylene/α-olefin copolymer A1! (or A2!) and the ethylene/α-olefincopolymer B1! by the use of plural polymerizers.

The ethylene/α-olefin copolymer composition according to the inventionmay be processed by a conventional molding method, for example,air-cooling inflation molding, two-stage air-cooling inflation molding,high-speed inflation molding, T-die film molding or water-coolinginflation molding, to obtain films. The films thus obtained areexcellent in transparency and mechanical strength, and retain propertiesinherent in general LLDPE, such as heat-sealing properties, hot-tackproperties and heat resistance. Further, the films are free from surfacestickiness because the ethylene/α-olefin copolymers A1!, A2! and B1!have a prominently narrow composition distribution. Moreover, because ofthe high melt tension, the composition is excellent in bubble stabilityduring the inflation molding.

The films obtained from the ethylene/α-olefin copolymer compositionaccording to the invention are suitable for various packaging bags suchas standard bags, sugar bags, packaging bags for oily goods andpackaging bags for moist goods, and agricultural materials. Further,because of their high adhesion strength to nylon, polyester, etc., thefilms may be used as multi-layer films by laminating them on thesesubstrates.

Next, the graft modified ethylene/α-olefin copolymer composition will bedescribed below in detail.

The graft modified ethylene/α-olefin copolymer composition of theinvention is a composition obtained by graft copolymerizing anethylene/α-olefin copolymer Composition C! with a polar monomer. Theethylene/α-olefin copolymer composition C! comprises anethylene/α-olefin copolymer A3! described later and the aforesaidethylene/α-olefin copolymer B1!.

Ethylene/α-olefin copolymer A3!!

The ethylene/α-olefin copolymer A3! for forming the ethylene/α-olefincopolymer composition C! is a random copolymer of ethylene with anα-olefin of 3 to 20 carbon atoms which is similar to those describedbefore.

In the ethylene/α-olefin copolymer A3!, it is desired that constituentunits derived from ethylene are present in an amount of 50 to 100% byweight, preferably 55 to 99% by weight, more preferably 65 to 98% byweight, particularly preferably 70 to 96% by weight; and constituentunits derived from an α-olefin of 3 to 20 carbon atoms are present in anamount of 0 to 50% by weight, preferably 1 to 45% by weight, morepreferably 2 to 35% by weight, particularly preferably 4 to 30% byweight.

The ethylene/α-olefin copolymer A3! preferably has the aforementionedproperties (A-i) and (A-ii), more preferably has the properties (A-i) to(A-vi), and particularly preferably has the properties (A-i) to(A-viii).

The ethylene/α-olefin copolymer A3! can be prepared by copolymerizingethylene with an α-olefin of 3 to 20 carbon atoms in the presence of acatalyst for olefin polymerization prepared by contacting theorganoaluminum oxy-compound (a), the transition metal compound (b'), thecarrier and if necessary the organoaluminum compound (c), preferably inthe presence of a catalyst for olefin polymerization prepared bycontacting the component (a), at least two kinds of the transition metalcompounds (b), the carrier and if necessary the organoaluminum compound(c), in such a manner that the resultant copolymer has a density of0.850 to 0.980 g/cm³.

In the preparation of the ethylene/α-olefin copolymer A3!, it is desiredto use a combination of at least one kind of a transition metal compoundrepresented by the above formula b-I! and at least one kind of atransition metal compound represented by the above formula b-II! as thetransition metal compound (b). In concrete, preferably used are acombination of bis(1,3-n-butylmethylcyclopentadienyl)zirconiumdichloride and bis(1,3-dimethylcyclopentadienyl)zirconium dichloride, acombination of bis(1,3-n-propylmethylcyclopentadienyl)zirconiumdichloride and bis(1,3-dimethylcyclopentadienyl)zirconium dichloride,and a combination of bis(n-butylcyclopentadienyl)zirconium dichlorideand bis(1,3-dimethylcyclopentadienyl)zirconium dichloride.

A molar ratio (b-I)/(b-II)! of at least one kind of the transition metalcompound (b-I) represented by the formula b-I! to at least one kind ofthe transition metal compound (b-II) represented by the formula b-II! isin the range of 99/1 to 50/50, preferably 97/3 to 70/30, more preferably95/5 to 75/25, most preferably 90/10 to 80/20.

The catalyst used for preparing the ethylene/α-olefin copolymer A3! canbe obtained in a manner similar to that for the catalyst used forpreparing the ethylene/α-olefin copolymers A1! and A2!.

In the catalyst for olefin polymerization used for preparing theethylene/α-olefin copolymer A3!, the transition metal atom derived fromthe component (b') (or the component (b)) is desirably supported in anamount of 5×10⁻⁶ to 5×10⁻⁴ g.atom, preferably 10⁻⁵ to 2×10⁻⁴ g.atom, per1 g of the carrier; and the aluminum atom derived from the component (a)and the component (c) is desirably supported in an amount of 10⁻³ to5×10⁻² g.atom, preferably 2×10⁻³ to 2×10⁻² g.atom, per 1 g of thecarrier.

The catalyst used for preparing the ethylene/α-olefin copolymer A3! maybe a prepolymerized catalyst obtained by prepolymerizing an olefin inthe presence of the component (a), the component (b') (or the component(b)), the carrier, and if necessary the component (c). Thisprepolymerized catalyst can be obtained in a manner similar to that forthe prepolymerized catalyst used for preparing the ethylene/α-olefincopolymers A1! and A2!.

In the prepolymerized catalyst, the component (b') (or the component(b)) is desirably supported in an amount of about 5×10⁻⁶ to 5×10⁻⁴g.atom, preferably 10⁻⁵ to 2×10⁻⁴ g.atom, in terms of the transitionmetal atom, per 1 g of the carrier; and the aluminum atom (Al) derivedfrom the component (a) and the component (c) is desirably supported insuch an amount that the molar ratio (Al/M) of the aluminum atom (Al)derived from the component (a) and the component (c) to the transitionmetal atom (M) derived from the component (b) is in the range of 5 to200, preferably 10 to 150.

The ethylene/α-olefin copolymer A3! can be obtained by copolymerizingethylene with the α-olefin of 3 to 20 carbon atoms described beforeunder the same conditions as described before in the presence of, forexample, a catalyst for olefin polymerization comprising the component(a), the component (b') (or the component (b)) and the carrier.

Ethylene/α-olefin copolymer composition!

The ethylene/α-olefin copolymer composition C! comprises theethylene/α-olefin copolymer A3! and the ethylene/α-olefin copolymer B1!which is different from the ethylene/α-olefin copolymer A3!. In thiscomposition, it is desired that the ethylene/α-olefin copolymer A3! iscontained in an amount of 20 to 90% by weight, preferably 40 to 75% byweight, and the ethylene/α-olefin copolymer B1! is contained in anamount of 10 to 80% by weight, preferably 25 to 60% by weight.

The ethylene/α-olefin copolymers A3! and B1! are used in an appropriatecombination so that the ratio ( A3!/ B1!) in the density of theethylene/α-olefin copolymer A3! to the ethylene/α-olefin copolymer B1!is preferably less than 1, more preferably in the range of 0.930 to0.999.

The ethylene/α-olefin copolymer composition C! preferably has thefollowing properties (ii) to (vii).

(ii) The density (d) is in the range of usually 0.850 to 0.980 g/cm³,preferably 0.890 to 0.955 g/cm³, more preferably 0.900 to 0.950 g/cm³.

(iii) The melt flow rate (MFR) under the conditions of a temperature of190° C. and a load of 2.16 kg is in the range of usually 0.1 to 100 g/10min, preferably 0.2 to 50 g/10 min.

(iv) The melt tension (MT (g)) at 190° C. and the melt flow rate (MFR)satisfy the relation:

    MT≧-2.2×MFR.sup.-0.84.

(v) The flow index (FI (l/sec)) defined by a shear rate which is givenwhen a shear stress at 190° C. reaches 2.4×10⁶ dyne/cm² and the meltflow rate (MFR) satisfy the relation:

    FI>100×MFR,

preferably

    FI>130×MFR,

more preferably

    FI>150×MFR.

(vi) The temperature (Tin (° C.)) at which the endothermic curve of thecomposition measured by a differential scanning calorimeter (DSC) showsthe maximum peak and the density (d) satisfy the relation:

    Tm<400×d-250,

preferably

    Tm<450×d-297,

more preferably Tm<500×d-344,

particularly preferably

    Tm<550×d-391.

(vii) The quantity fraction (W (% by weight)) of a n-decane-solublecomponent at room temperature (23° C.) and the density (d) satisfy therelation:

in the case of MFR≦10 g/10 min:

    W<80×exp(-100(d-0.88))+0.1,

preferably

    W<60×exp(-100d-0.88))+0.1,

more preferably

    W<40×exp(-100d-0.88))+0.1,

and in the case of

    MFR>10 g/10 min:

    W<80×(MFR-9).sup.0.26 ×exp(-100d-0.88))+0.1.

The ethylene/α-olefin copolymer composition C! can be prepared by knownprocesses, for example, processes similar to those described in theabove mentioned ethylene/α-olefin copolymer composition.

The graft modified ethylene/α-olefin copolymer composition I!!

The graft modified ethylene/α-olefin copolymer composition I! of theinvention can be obtained by causing such an ethylene/α-olefin copolymercomposition C! as mentioned above to react with a polar monomerdescribed below in the presence of a radical initiator.

Examples of the polar monomer include hydroxyl group-containingethylenic unsaturated compounds, amino group-containing ethylenicunsaturated compounds, epoxy group-containing ethylenic unsaturatedcompounds, aromatic vinyl compounds, unsaturated carboxylic acids,derivatives of these acids, vinyl ester compounds and vinyl chloride.

Concrete examples of the hydroxyl group-containing ethylenic unsaturatedcompounds include (meth)acrylates, such as hydroxyethyl (meth)acrylate,2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth)acrylate,2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl(meth) acrylate, glycerol mono(meth) acrylate, pentaerythritolmono(meth) acrylate, trimethylolpropane mono(meth)acrylate,tetramethylolethane mono(meth)acrylate, butanediol mono(meth) acrylate,polyethylene glycol mono(meth)acrylate and 2-(6-hydroxyhexanoyloxy)ethylacrylate; and other compounds, such as 10-undecene-1-ol, 1-octene-3-ol,2-methanol norbornene, hydroxystyrene, hydroxethyl vinyl ether,hydroxybutyl vinyl ether, N-methylolacrylamide, 2-(meth)acryloyloxyethylacid phosphate, glycerol monoallyl ether, allyl alcohol,allyloxyethanol, 2-butene-l,4-diol and glycerol monoalcohol.

The amino group-containing ethylenic unsaturated compound is a compoundhaving an ethylenic double bond and an amino group. An example of suchcompound is a vinyl monomer having at least one substituted orunsubstituted amino group represented by the following formula: ##STR4##wherein R¹ is hydrogen, a methyl group or an ethyl group; and R² ishydrogen, an alkyl group having 1 to 12 carbon atoms, preferably 1 to 8carbon atoms, or a cycloalkyl group having 6 to 12 carbon atoms,preferably 6 to 8 carbon atoms. These alkyl and cycloalkyl groups mayfurther have a substituent group.

Concrete examples of such amino group-containing ethylenic unsaturatedcompound include alkyl acrylate type and alkyl methacrylate typederivatives, such as aminoethyl (meth)acrylate, propylaminoethyl(meth)acrylate, dimethylaminoethyl methacrylate, aminopropyl (meth)acrylate, phenylaminoethyl methacrylate and cyclohexylaminoethylmethacrylate; vinyl amine type derivatives, such as N-vinyldiethylamineand N-acetylvinylamine; allylamine type derivatives, such as allylamine,methacrylamine, N-methylacrylamine, N,N-dimethylacrylamide andN,N-dimethylaminopropylacrylamide; acrylamide type derivatives, such asacrylamide and N-methylacrylamide; aminostyrenes, such asp-aminostyrene; and other compounds, such as 6-aminohexyl succinimideand 2-aminoethyl succinimide.

The epoxy group-containing ethylenic unsaturated compound is a monomerhaving a polymerizable unsaturated bond and at least one epoxy group inone molecule.

Concrete examples of such epoxy group-containing ethylenic unsaturatedcompound include:

glycidyl acrylate and glycidyl methacrylate;

mono and alkylglycidyl esters of dicarboxylic acids (number of carbonatoms of the alkyl group in the case of monoglycidyl ester: 1-12), suchas monoglycidyl maleate, diglycidyl maleate, monoglycidyl fumarate,diglycidyl fumarate, monoglycidyl crotonate, diglycidyl crotonate,monoglycidyl tetrahydrophthalate, diglycidyl tetrahydrophthalate,monoglycidyl itaconate, diglycidyl itaconate, monoglycidylbutenetricarboxylate, diglycidyl butenetricarboxylate, monoglycidylcitraconate, diglycidyl citraconate, monoglycidyl ester ofendo-cis-bicyclo 2.2.1!hept-5-ene-2,3-dicarboxylic acid (nadic acid™),diglycidyl ester thereof, monoglycidyl ester of endo-cis-bicyclo2.2.1!hept-5-ene-2-methyl-2,3-dicarboxylic acid (methylnadic acid™),diglycidyl ester thereof, monoglycidyl allylsuccinate and diglycidylallylsuccinate; and

other compounds, such as alkylglycidyl p-styrenecarboxylate, allylglycidyl ether, 2-methylallyl glycidyl ether, styrene-p-glycidyl ether,3,4-epoxy-1-butene, 3,4-epoxy-3-methyl-1-butene, 3,4-epoxy-1-pentene,3,4-epoxy-3-methyl-1-pentene, 5,6-epoxy-1-hexene and vinylcyclohexenemonoxide.

The aromatic vinyl compound is, for example, a compound represented bythe following formula: ##STR5## wherein R¹ and R² are each independentlyhydrogen or an alkyl group of 1 to 3 carbon atoms (concretely, methyl,ethyl, propyl or isopropyl), R³ is a hydrocarbon group of 1 to 3 carbonatoms (concretely, methyl, ethyl, propyl or isopropyl) or a halogen atom(concretely, chlorine, bromine or iodine), and n is an integer of 0 to5, preferably an integer of 1 to 5.

Concrete examples of such aromatic vinyl compound include styrene,α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene,p-chlorostyrene, m-chlorostyrene, p-chloromethylstyrene,4-vinylpyridine, 2-vinylpyridine, 5-ethyl-2-vinylpyridine,2-methyl-5-vinylpyridine, 2-isopropenylpyridine, 2-vinylquinoline,3-vinylisoquinoline, N-vinylcarbazole and N-vinylpyrrolidone.

Examples of the unsaturated carboxylic acids include unsaturatedcarboxylic acids, such as acrylic acid, methacrylic acid, maleic acid,fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid,crotonic acid, isocrotonic acid, norbornenedicarboxylic acid and bicyclo2,2,1!hept-2-ene-5,6-dicarboxylic acid; anhydrides of these acids; andderivatives of these acids (e.g., acid halides, amides, imides andesters). Concrete examples of such compounds include malenyl chloride,malenyl imide, maleic anhydride, itaconic anhydride, citraconicanhydride, tetrahydrophthalic anhydride, bicyclo2,2,1!hept-2-ene-5,6-dicarboxylic anhydride, dimethyl maleate,monomethyl maleate, diethyl maleate, diethyl fumarate, dimethylitaconate, diethyl citraconate, dimethyl tetrahydrophthalate, dimethylbicyclo 2,2,1!hept-2-ene-5,6-dicarboxylate, hydroxyethyl (meth)acrylate,hydroxypropyl. (meth)acrylate, glycidyl (meth)acrylate, aminoethylmethacrylate and aminopropyl methacrylate.

Of these, preferred are (meth) acrylic acid, maleic anhydride,hydroxyethyl (meth)acrylate, glycidyl methacrylate and aminopropyulmethacrylate.

Examples of the vinyl ester compounds include vinyl acetate, vinylpropionate, vinyl n-butyrate, vinyl isobutyrate, vinyl pivalate, vinylcaproate, vinyl versatate, vinyl laurate, vinyl stearate, vinylbenzoate, vinyl p-t-butyl benzoate, vinyl salicylate and vinylcyclohexanecarboxylate.

The polar monomer is used in an amount of usually 1 to 100 parts byweight, preferably 5 to 80 parts by weight, per 100 parts by weight ofthe ethylene/α-olefin copolymer composition C!.

As the radical initiator, organic peroxides and azo compounds can beemployed.

Examples of the organic peroxides include dicumyl peroxide, di-t-butylperoxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis (t-butylperoxy)hexyne-3, 1,3-bis(t-butylperoxyisopropyl) benzene,1,1-bis(t-butylperoxy)valerate, benzoyl peroxide, t-butylperoxybenzoate, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide,decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide,2,4-dichlorobenzoyl peroxide and m-toluyl peroxide. Examples of the azocompounds include azoisobutyronitrile and dimethylazoisobutyronitrile.

The radical initiator is desirably used in an amount of 0.001 to 10parts by weight per 100 parts by weight of the ethylene/α-olefincopolymer composition C!.

The radical initiator may be used by mixing it per se with theethylene/α-olefin copolymer composition C! and the polar monomer, or maybe used in the form of a solution containing it in a small amount of anorganic solvent. There is no specific limitation on the organic solventused herein, and any organic solvents may be used as far as they cabdissolve the radical initiator. Examples of such organic solventsinclude aromatic hydrocarbon type solvents, such as benzene, toluene andxylene; aliphatic hydrocarbon type solvents, such as pentane, hexane,heptane, octane, nonane and decane; alicyclic hydrocarbon type solvents,such as cyclohexane, methylcyclohexane and decahydronaphthalene;chlorinated hydrocarbon type solvents, such as chlorobenzene,dichlorobenzene, trichlorobenzene, methylene chloride, chloroform,carbon tetrachloride and tetrachloroethylene; alcohol type solvents,such as methanol, ethanol, n-propanol, iso-propanol, n-butanol,sec-butanol and tert-butanol; ketone type solvents, such as acetone,methyl ethyl ketone and methyl isobutyl ketone; ester type solvents,such as ethyl acetate and dimethyl phthalate; and ether type solvents,such as dimethyl ether, diethyl ether, di-n-amyl ether, tetrahydrofuranand dioxyanisole.

In the graft modification of the ethylene/α-olefin copolymer compositionC!, a reducing material may be employed. The reducing material serves toincrease the graft amount in the resultant graft modifiedethylene/α-olefin copolymer composition.

Examples of the reducing material include iron(II) ion, chromium ion,cobalt ion, nickel ion, palladium ion, sulfite, hydroxylamine, hydrazineand a compound containing --SH, SO₃ H, --NHNH₂ or --COCH(OH)--.

Concrete examples of such reducing material include ferrous chloride,potassium bichromate, cobalt chloride, cobalt naphthenate, palladiumchloride, ethanolamine, diethanolamine, N,N-dimethylaniline, hydrazine,ethylmercaptan, benzenesulfonic acid and p-toluenesulfonic acid.

The reducing material is used in an amount of usually 0.001 to 5 partsby weight, preferably 0.1 to 3 parts by weight, per 100 parts by weightof the ethylene/α-olefin copolymer composition C!.

The graft modification of the ethylene/α-olefin copolymer composition C!can be carried out by a conventionally known process. For example, theethylene/α-olefin copolymer composition C! is dissolved in an organicsolvent, and to the resultant solution are added the polar monomer, theradical initiator, etc. to perform reaction at a temperature of 70° to200° C., preferably 80° to 190° C., for a period of 0.5 to 15 hours,preferably 1 to 10 hours.

As the organic solvent used in the graft modification of theethylene/α-olefin copolymer composition C!, any organic solvents may beused without any specific limitation as far as they can dissolve theethylene/α-olefin copolymer composition C!.

Concrete examples of such organic solvents include aromatic hydrocarbontype solvents, such as benzene, toluene and xylene; and aliphatichydrocarbon type solvents, such as pentane, hexane and heptane.

In the graft modified ethylene/α-olefin copolymer composition preparedabove, the graft amount of the graft group derived from the polar groupis usually in the range of 0.1 to 50% by weight, preferably 0.2 to 30%by weight.

The graft modified ethylene/α-olefin copolymer composition may also beprepared by causing the ethylene/α-olefin copolymer composition to reactwith the polar monomer in an extruder or the like without using anysolvent. In this case, the reaction temperature is generally not lowerthan the melting point of the ethylene/α-olefin copolymer, concretely,in the range of 120° to 250 ° C., and the reaction time is generally inthe range of 0.5 to 10 minutes.

The ethylene copolymer composition according to the present invention isformed from the above-mentioned graft modified ethylene/α-olefincopolymer composition I! and polyolefin II!.

Polyolefin II!!

The polyolefin II! used for forming the ethylene copolymer compositionof the invention is a homopolymer of ethylene or an α-olefin of 3 to 20carbon atoms, or a copolymer of at least two kinds of monomers selectedfrom ethylene and α-olefins of 3 to 20 carbon atoms.

Examples of the α-olefins of 3 to 20 carbon atoms include propylene,1-butene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene,3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene,1-heptene, methyl-1-hexene, dimethyl-1-pentene, trimethyl-1-butene,ethyl-1-pentene, 1-octene, methyl-1-pentene, dimethyl-1-hexene,trimethyl-1-pentene, ethyl-1-hexene, methylethyl-1-pentene,diethyl-1-butene, propyl-1-pentene, 1-decene, methyl-1-nonene,dimethyloctene, trimethyl-1-heptene, ethyl-1-octene,methylethyl-1-heptene, diethyl-1-hexene, 1-dodecene and hexadodecene.

The polyolefin II! is preferably a homopolymer of ethylene or anα-olefin of 3 to 8 carbon atoms, or a copolymer of at least two kinds ofmonomers selected from ethylene and α-olefins of 3 to 8 carbon atoms.

The polyolefin II! used for forming the ethylene copolymer compositionof the invention contains repeating units derived from ethylene or anα-olefin of 3 to 20 carbon atoms in an amount of usually not less than50% by mol, preferably not less than 80% by mol, more preferably 100% bymol.

The polyolefin II! may further contain repeating units derived fromother compounds polymerizable with the α-olefin in addition to therepeating units derived from ethylene or the α-olefin of 3 to 20 carbonatoms.

Examples of the other compounds include chain polyene compounds, cyclicpolyene compounds and cyclic monoene compounds.

These polyene compounds are those having at least two conjugated ornon-conjugated olefinic double bonds.

Examples of the chain polyene compounds include 1,4-hexadiene,1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 2,4,6-octatriene,1,3,7-octatriene, 1,5,9-decatriene and divinylbenzene.

Examples of the cyclic polyene compounds include 1,3-cyclopentadiene,1,3-cyclohexadiene, 5-ethyl-1,3-cyclohexadiene, 1,3-cycloheptadiene,dicyclopentadiene, dicyclohexadiene, 5-ethylidene-2-norbornene,5-vinyl-2-norbornene, 5-isopropylidene-2-norbornene, methylhydroindene,2,3-diisopropylidene-5-norbornene,2-ethylidene-3-isopropylidene-5-norbornene,2-ethylidene-3-isopropylidene-5-norbornene and2-propenyl-2,5-norbornadiene.

Examples of the cyclic monoene compounds include:

monocycloalkenes, such as cyclopropene, cyclobutene, cyclopentene,cyclohexene, 3-methylcyclohexene, cycloheptene, cyclooctene,cyclodecene, cyclododecene, tetracyclodecene, octacyclodecene andcycloeicosene;

bicycloalkenes, such as norbornene, 5-methyl-2-norbornene,5-ethyl-2-norbornene, 5-isobutyl-2-norbornene,5,6-dimethyl-2-norbornene, 5,5,6-trimethyl-2-norbornene and 2-bornene;

tricycloalkenes, such as 2,3,3a,7a-tetrahydro-4,7-methano-1H-indene and3a,5,6,7a-tetrahydro-4,7-methano-1H-indene;

tetracycloalkenes, such as1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-propyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-hexyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-stearyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2,3-dimethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-methyl-3-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-chloro-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-bromo-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene,2-fluoro-1,4,5,8-dimethano-1,2,3,4,4a, 5,8,8a-octahydronaphthalene and2,3-dichloro-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene;and

polycycloalkenes, such as hexacyclo 6,6,1,1³.6,1¹⁰.13,0².7,0⁹.14!heptadecene-4, pentacyclo 8,8,1².9,1⁴.7 1,¹¹.18, 0,0³.8,0¹².17!heneicosene-5 and octacyclo 8,8,1².9,1⁴.7,1¹¹.18,0,0³.8,0¹².17!docosene-5.

The polyolefin II! may further contain constituent units derived fromstyrene or substituted styrene.

It is desired that the polyolefin II! has an intrinsic viscosity η!, asmeasured in decalin at 135° C., of usually 0.4 to 7 dl/g, preferably 0.5to 5 dl/g.

The polyolefin II! for forming the ethylene copolymer composition of theinvention can be prepared by polymerizing or copolymerizing theabove-mentioned α-olefin by a conventionally known process. The(co)polymerization reaction may be carried out either in a gas phase(gas phase process) or in a liquid phase (liquid phase process).

Ethylene copolymer composition!

The ethylene copolymer composition according to the invention comprisesthe above-mentioned graft modified ethylene/α-olefin copolymercomposition I! and polyolefin II!. A weight ratio ( I!: II!) between thegraft modified ethylene/α-olefin copolymer composition I! and thepolyolefin II! is in the range of 1:99 to 99:1, preferably 2:98 to 98:2.

The ethylene copolymer composition of the invention may contain variousadditives if desired, for example, weathering stabilizer, heatstabilizer, antistatic agent, anti-slip agent, anti-blocking agent,anti-fogging agent, lubricant, pigment, dye, nucleating agent,plasticizer, anti-aging agent, hydrochloric acid absorbent andantioxidant, provided that the object of the invention is not marred.

The ethylene copolymer composition according to the present inventioncan be prepared by known processes, for example, processes describedbelow.

(1) A process of mechanically blending the graft modifiedethylene/α-olefin copolymer composition I!, the polyolefin II!, and ifnecessary, other optional components using an extruder, a kneader or thelike.

(2) A process comprising dissolving the graft modified ethylene/α-olefincopolymer composition I!, the polyolefin II!, and if necessary, otheroptional components in an appropriate good solvent (e.g., hydrocarbonsolvent such as hexane, heptane, decane, cyclohexane, benzene, tolueneand xylene) and, then removing the solvent from the resulting solution.

(3) A process comprising independently dissolving the graft modifiedethylene/α-olefin copolymer composition I!, the polyolefin II!, and ifnecessary, other optional components in an appropriate good solvent toprepare solutions, then mixing the solutions, and removing the solventfrom the resulting mixture.

(4) A process in any combination of the above processes (1) to (3).

The the ethylene copolymer composition according to the invention may beprocessed by a conventional molding method, for example, normal pressmolding, air-cooling inflation molding, two-stage air-cooling inflationmolding, high-speed inflation molding, T-die film molding orwater-cooling inflation molding, to obtain films. The films thusobtained are excellent in transparency and mechanical strength, andretain properties inherent in general LLDPE, such as heat-sealingproperties, hot-tack properties and heat resistance. Further, the filmsare free from surface stickiness because the ethylene/α-olefin copolymerA3! and the ethylene/α-olefin copolymer B1! have a prominently narrowcomposition distribution. Moreover, because of low stress within thehigh-shear region, the ethylene copolymer composition can be extruded athigh speed, and thus consumption of electric power is small, resultingin economical advantage.

The films obtained from the graft modified ethylene/α-olefin copolymerand the ethylene copolymer composition according to the invention aresuitable for various packaging bags such as standard bags, sugar bags,packaging bags for oily goods and packaging bags for moist goods, andagricultural materials. Further, because of their high adhesion strengthto nylon, polyester, a metal foil, etc., the films may be used asmulti-layer films by laminating them on these substrates.

Next, the multi-stage olefin polymerization process according to thepresent invention will be described below.

The multi-stage olefin polymerization process of the inventioncomprises:

a stage (1) of preparing an ethylene/α-olefin copolymer A1! bycopolymerizing ethylene with an α-olefin of 3 to 20 carbon atoms in thepresence of a catalyst for olefin polymerization (C1) comprising:

(a) an organoaluminum oxy-compound,

(b-I) at least one kind of a transition metal compound represented bythe above formula b-I!, and

(b-II) at least one kind of a transition metal compound represented bythe above formula b-II!; and

a stage (2) of preparing an ethylene/α-olefin copolymer B1! bycopolymerizing ethylene with an α-olefin of 3 to 20 carbon atoms in adifferent polymerizer from that for the copolymerization reaction of thestage (1) in the presence of a catalyst for olefin polymerization (C2)comprising (a) an organoaluminum oxy-compound and (b') a compound ofGroup IV transition metal of the periodic table containing a ligandhaving a cyclopentadienyl skeleton.

The catalyst for olefin polymerization (C1) used for the invention is acatalyst (C1-i) comprising the component (a) and the component (b) (thecomponent (b-I) and the component (b-II)); a solid catalyst (C1-ii) inwhich the component (a) and the component (b) are supported on thecarrier; a prepolymerized catalyst (Cl-iii) obtained by prepolymerizingan olefin on the solid catalyst (C1-ii) (solid catalyst component); acatalyst comprising the catalyst (Cl-i) (catalyst component) and thecomponent (c); a catalyst comprising the solid catalyst (C1-ii) (solidcatalyst component) and the component (c); or a catalyst comprising theprepolymerized catalyst (C1-iii) (prepolymerized catalyst component) andthe component (c).

The catalyst for olefin polymerization (C2) used for the invention is acatalyst (C2-i) comprising the component (a) and the component (b-III);a solid catalyst (C2-ii) in which the component (a) and the component(b-III) are supported on the carrier; a prepolymerized catalyst (C2-iii)obtained by prepolymerizing an olefin on the solid catalyst (C2-ii)(solid catalyst component); a catalyst comprising the catalyst (C2-i)and the component (c); a catalyst comprising the solid catalyst (C2-ii)(solid catalyst component) and the component (c); or a catalystcomprising the prepolymerized catalyst (C2-iii) (prepolymerized catalystcomponent) and the component (c).

The catalyst (C1-i) and the catalyst (C2-i) can be prepared by mixingand contacting each catalyst components in or outside a polymerizer.Further, they can be prepared by a process comprising making thecomponent (a) solid component, contacting the resultant solid componentwith the component (b) (or the component (b-III)) to form a solidcatalyst and adding the solid catalyst to the polymerization system, orby a process comprising initially contacting the component (a) with thecomponent (b) (or the component (b-III)) to form a solid catalyst andadding the solid catalyst to the polymerization system.

The catalyst (C1-i) can be prepared by mixing and contacting thecomponent (a) with the component (b) and if necessary the component (c)in an inert solvent. The contact between each components may be carriedout in an arbitrarily selected order. In the case of the contact betweenthe component (a) and the component (b), it is preferred to add thecomponent (b) to a suspenstion of the component (a). Further, it ispreferred that at least two kinds of the transition metal compounds arebeforehand mixed to form the component (b) and then the component (b) iscontacted with other components.

Examples of the inert hydrocarbon solvent used for preparing thecatalyst (C1-i) include the same ones as used for preparing theaforementioned catalysts.

In the contact of the component (a) with the component (b) and ifnecessary the component (c), the concentration of aluminum in thecomponent (a) is in the range of about 0.1 to 5 mol/l, preferably 0.3 to3 mol/l. An atomic ratio (Al/transition metal) of the aluminum atom (Al)in the component (a) to the transition metal in the component (b) is inthe range of usually 10 to 500, preferably 20 to 200. An atomic ratio(Al-c/Al-a) of the aluminum atom (Al-c) in the component (c) which isoptionally used to the aluminum atom (Al-a) in the component (a) is inthe range of usually 0.02 to 3, preferably 0.05 to 1.5. The temperaturefor contacting the component (a) with the component (b) and if necessarythe component (c) is in the range of usually -50° to 150 ° C.,preferably -20° to 120 ° C., and the period of time therefor is in therange of 1 minute to 50 hours, preferably 10 minutes to 25 hours.

The catalyst (C2-ii) used for the invention can be prepared using thecomponent (a), the component (b-III) and if necessary the component (c)in a manner similar to that for the above catalyst (C1-i).

In the catalyst (C1-i) and the catalyst (C2-i) prepared above, thetransition metal atom derived from the component (b) (or the component(b')) is desirably contained in an amount of 5×10⁻⁶ to 5×10⁻⁴ g.atom,preferably 10⁻⁵ to 2×10⁻⁴ g.atom, per 1 g of the catalyst, and thealuminum atom derived from the component (a) and the component (c) isdesirably contained in an amount of 10⁻² to 2.5×10⁻² g.atom, preferably1.5×10⁻² to 2×10⁻² g.atom, per 1 g of the catalyst.

The solid catalyst (C1-ii) used for the invention is the same catalystfor olefin polymerization as the aforementioned solid catalyst (1), andthe solid catalyst (C2-ii) used for the invention is the same catalystfor olefin polymerization as the aforementioned solid catalyst (2).

The prepolymerized catalyst (C1-iii) used for the invention is the samecatalyst for olefin polymerization as the aforementioned prepolymerizedcatalyst (1), and the prepolymerized catalyst (C2-iii) used for theinvention is the same catalyst for olefin polymerization as theaforementioned prepolymerized catalyst (2).

The multi-stage olefin polymerization process according to the inventioncomprises a stage (1) of copolymerizing ethylene with an α-olefin of 3to 20 carbon atoms in the presence of the above-mentioned catalyst forolefin polymerization (C1) to prepare the ethylene/α-olefin copolymerA1! and a stage (2) of copolymerizing ethylene with an α-olefin of 3 to20 carbon atoms in the presence of the above-mentioned catalyst forolefin polymerization (C2) to prepare the ethylene/α-olefin copolymerB1!.

Examples of the α-olefin of 3 to 20 carbon atoms used herein includepropylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene,1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and1-eicosene.

In the invention, copolymerization of ethylene with the α-olefin may becarried out either in a gas phase or in a liquid phase such as slurry.In the slurry polymerization, an inert hydrocarbon may be used as asolvent, or the olefin itself may be used as a solvent.

Examples of the inert hydrocarbon solvent used for the slurrypolymerization include the same ones as described before. Of variousinert hydrocarbon solvents, preferred are aliphatic hydrocarbons,alicyclic hydrocarbons and petroleum fractions.

In the slurry polymerization or the gas phase polymerization, thecatalyst for olefin polymerization (C1) or (C2) is used in such anamount that the concentration of the transition metal atom in thepolymerization reaction system is in the range of usually 10⁻⁸ to 10⁻³g.atom/l, preferably 10⁻⁷ to 10⁻⁴ g.atom/l.

In the polymerization, an organoaluminum oxy-compound which is the sameas the component (a) and/or the organoaluminum compound (c) may beadded. In this case, the atomic ratio (Al/M) of the aluminum atom (Al)derived from the organoaluminum oxy-compound and the organoaluminumcompound to the transition metal atom (M) derived from the component (b)(or the component (b')) is in the range of 5 to 300, preferably 10 to200, more preferably 15 to 150.

In the invention, the temperature for the slurry polymerization is inthe range of usually -50° to 100 ° C., preferably 0° to 90 ° C., whilethe temperature for the gas phase polymerization is in the range ofusually 0° to 120° C., preferably 20° to 100 ° C.

The polymerization pressure is in the range of usually atmosphericpressure to 100 kg/cm², preferably 2 to 50 kg/cm².

In the multi-stage olefin polymerization process of the invention,plural polymerizers combined with each other in series are used. First,the ethylene/α-olefin copolymer A1! is prepared in the presence of thecatalyst for olefin polymerization (C1) in a polymerizer, and then theethylene/α-olefin copolymer B1! is prepared in the presence of thecatalyst for olefin polymerization (C2) in a polymerizer different fromthe polymerizer of the above copolymerization. Otherwise, theethylene/α-olefin copolymer B1! is first prepared in the presence of thecatalyst for olefin polymerization (C2) in a polymerizer, and then theethylene/α-olefin copolymer A1! is prepared in the presence of thecatalyst for olefin polymerization (C1) in a polymerizer different fromthe polymerizer of above copolymerization. In the invention, pluralpolymerizers combined with each other in parallel may be used. In thiscase, it is possible to prepare the ethylene/α-olefin copolymer A1! andthe ethylene/α-olefin copolymer B1! in different polymerizers, followedby blending the ethylene/α-olefin copolymer All with theethylene/α-olefin copolymer B1!.

In the multi-stage olefin polymerization process of the invention, whenthe ethylene/α-olefin copolymer A1! is prepared by a slurrypolymerization, the polymerization temperature is in the range ofusually -50° to 90 ° C., preferably 0° to 85° C., but when the copolymerA1! is prepared by a gas phase polymerization, the polymerizationtemperature is in the range of usually 0° to 100 ° C., preferably 20° to90 ° C. When the ethylene/α-olefin copolymer B1! is prepared by a slurrypolymerization, the polymerization temperature is in the range ofusually -30° to 100 ° C., preferably 20° to 90 ° C., but when thecopolymer B1! is prepared by a gas phase polymerization, thepolymerization temperature is in the range of usually 20° to 120° C.,preferably 30° to 100° C.

The ethylene/α-olefin copolymer composition prepared by the multi-stageolefin polymerization process of the invention comprises theethylene/α-olefin copolymer A1! and the ethylene/α-olefin copolymer B1!.In this composition, it is desired that the ethylene/α-olefin copolymerA1! is contained in an amount of 20 to 90% by weight, preferably 40 to75% by weight, and the ethylene/α-olefin copolymer B1! is contained inan amount of 10 to 80% by weight, preferably 25 to 60% by weight.

The ethylene/α-olefin copolymer composition is prepared in such a mannerthat the ratio ( A1!/ B1!) in the density of the ethylene/α-olefincopolymer A1! to the ethylene/α-olefin copolymer B1! is less than 1,preferably in the range of 0.930 to 0.999.

The ethylene/α-olefin copolymer composition preferably has the sameproperties as the aforesaid first ethylene/α-olefin copolymercomposition has.

The ethylene copolymer composition prepared by the multi-stage olefinpolymerization process of the invention may contain various additives ifdesired, for example, weathering stabilizer, heat stabilizer, antistaticagent, anti-slip agent, anti-blocking agent, anti-fogging agent,lubricant, pigment, dye, nucleating agent, plasticizer, anti-agingagent, hydrochloric acid absorbent and antioxidant.

The ethylene/α-olefin copolymer composition prepared by the multi-stageolefin polymerization process of the invention may be processed by aconventional molding method, for example, air-cooling inflation molding,two-stage air-cooling inflation molding, high-speed inflation molding,T-die film molding or water-cooling inflation molding, to obtain a film.The film thus obtained is excellent in transparency, mechanical strengthand blocking resistance, and retains properties inherent in generalLLDPE, such as heat-sealing properties, hot-tack properties and heatresistance. Further, the film is free from surface stickiness becausethe ethylene/α-olefin copolymers A1! and B1! have a prominently narrowcomposition distribution. The ethylene/α-olefin copolymer composition isexcellent in bubble stability in the inflation molding stage because ithas high melt tension. Moreover, because of low stress within thehigh-shear region, the composition can be extruded at a high speed andthe consumption of electric power is small, resulting in economicaladvantage.

The films obtained from the ethylene/α-olefin copolymer compositionprepared by the multi-stage olefin polymerization process of theinvention are suitable for various packaging bags such as standard bags,sugar bags, packaging bags for oily goods and packaging bags for moistgoods, and agricultural materials. Further, they can be used asmulti-layer films by laminating them on substrates such as a nylonsubstrate and a polyester substrate.

EFFECT OF THE INVENTION

The ethylene/α-olefin copolymer composition of the present invention isexcellent in heat stability and moldability. From this ethylene/α-olefincopolymer composition, a film having high transparency, high mechanicalstrength and high blocking resistance can be produced.

The graft modified ethylene/α-olefin copolymer composition of thepresent invention is excellent in moldability because it has high melttension and low stress within high-shear region. From this graftmodified ethylene/α-olefin copolymer composition, a film having hightransparency and good adhesion to highly polar materials can beproduced.

The ethylene copolymer composition of the present invention is a blendof the graft modified ethylene/α-olefin copolymer composition I! havinglow surface stickiness, high heat stability and good moldability, withthe polyolefin II!. Accordingly, this composition has high melt tensionand low stress within high-shear region, and therefore, it is excellentin moldability. From this ethylene copolymer composition, a film havinghigh transparency and good adhesion to highly polar materials can beproduced.

By the multi-stage olefin polymerization process of the presentinvention, there can be prepared an ethylene/α-olefin copolymercomposition which has high heat stability and good moldability and fromwhich a film of high transparency, high mechanical strength and highblocking resistance can be produced.

EXAMPLE!

The present invention is further described below with reference toexamples, but it should be construed that the present invention is in noway limited to those examples.

In the invention, physical properties of films were evaluated in thefollowing manner.

Haze

The haze was measured in accordance with ASTM-D-1003-61.

In the case of a graft modified ethylene/α-olefin copolymer composition,a pressed sheet having a thickness of 0.5 mm was prepared from thecomposition and the pressed sheet was measured on the haze in accordancewith ASTM-D-1003-61. In order to avoid an influence of the sheet surfaceon the measured value, the haze, namely, internal haze, was measured inthe state where the pressed sheet was immersed in an optical cell madeof quartz filled with benzyl alcohol.

Gloss

The gloss was measured in accordance with JIS Z8741.

Film Impact

The film impact was measured by means of a pendulum type film impacttester produced by Toyo Seiki Seisakusho K.K.

Adhesion Strength

A pressed sheet of a modified copolymer having a thickness of 100 μm wasused as a sample. The sample was heat sealed with two kinds of adherendsrespectively and was measured on the peel strength to evaluate theadhesion strength. One adherend is an aluminum foil having a thicknessof 0.5 mm, and the other adherend is a 6-nylon sheet having a thicknessof 1.0 mm. The heat sealing between the pressed sheet and the adherendwas conducted using a heat sealer under the conditions of a temperatureof 200 ° C., a load of 1 kg/cm² and a period of 60 sec. After the heatsealing, the pressed sheet with the adherend was cut to give a specimenhaving a width of 25 mm and a length of 150 mm. The adhesion strengthbetween the two layers (the modified polymer layer and the adherendlayer) of the specimen was measured by peeling the adherend layer in thedirection of 180° against the modified polymer layer at a peel rate of200 mm/min.

PREPARATION EXAMPLE 1

Preparation of an ethylene/α-olefin copolymer

Preparation of a catalyst component!

5.0 kg of silica having been dried at 250° C. for 10 hours was suspendedin 80 liters of toluene, and the resultant suspension was cooled to 0°C. Thereafter, to the suspension was dropwise added 28.7 liters of atoluene solution of methylaluminoxane (Al: 1.33 mol/l) over a period of1 hour. During the addition, the temperature of the system was kept at0° C. The reaction was successively carried out at 0° C. for 30 minutes.Then, the temperature of the system was elevated to 95° C. over a periodof 1.5 hours, and at the same temperature the reaction was conducted for20 hours. After that, the temperature of the system was lowered to 60°C., and the supernatant liquid was removed by decantation.

The solid portion obtained above was washed twice with toluene and thenagain suspended in 80 liters of toluene. To the reaction system weredropwise added 6.6 liters of a toluene solution ofbis(1,3-n-butylmethylcyclopentadienyl)zirconium dichloride (Zr: 34.0mmol/l) and 2.0 liters of a toluene solution ofbis(1,3-dimethylcyclopentadienyl)zirconium dichloride (Zr: 28.1 mmol/l)at 80° C. over a period of 30 minutes, and the reaction was furthercarried out at 80° C. for 2 hours. Then, the supernatant liquid wasremoved, and the residue was washed twice with hexane to obtain a solidcatalyst containing zirconium in an amount of 3.6 mg per 1 g of thesolid catalyst.

Preparation of a prepolymerized catalyst!

To 85 liters of hexane containing 1.7 mol of triisobutylaluminum wereadded 0.85 kg of the solid catalyst obtained above and 255 g of1-hexene. The resultant mixture was subjected to prepolymerization withethylene at 35° C. for 12 hours to obtain a prepolymerized catalyst inwhich polyethylene was prepolymerized in an amount of 10 g per 1 g ofthe solid catalyst. This ethylene polymer had an intrinsic viscosity η!of 1.74 dl/g.

Polymerization!

In a fluidized bed gas phase polymerizer of continuous type, ethylenewas copolymerized with 1-hexene at the total pressure of 20 kg/cm² -Gand a polymerization temperature of 70° C. To the polymerizer werecontinuously fed the prepolymerized catalyst prepared above at a feedrate of 0.18 mmol/hr in terms of zirconium atom and triisobutylaluminumat a feed rate of 10 mmol/hr while continuously feeding ethylene,1-hexene, hydrogen and nitrogen to maintain a constant gas composition(gas composition: 1-hexene/ethylene=0.032, hydrogen/ethylene=4.5×10⁻⁴,ethylene concentration=25%) during the polymerization.

Thus, an ethylene/1-hexene copolymer was obtained in an amount of 6.3kg/hr. The copolymer had MFR of 0.40 g/10 min, a density of 0.908 g/cm³and a decane-soluble portion quantity at room temperature of 0.54% byweight.

Physical properties of the ethylene/1-hexene copolymer are set forth inTable 1.

EXAMPLE 1

Preparation of a composition!

The ethylene/1-hexene copolymer (A-1) (density: 0.908 g/cm³, MRF: 0.40g/10 min) prepared in Preparation Example 1 and an ethylene/1-hexenecopolymer (B-1) prepared in the same manner as described in PreparationExample 1 except for adjusting the density and MFR of the copolymer tothose set forth in Table 1 were dry blended in a mixing ratio of 6/4(A-1)/(B-1)!. To the resultant blend were added 0.05 by weight oftri(2,4-di-t-butylphenyl)phosphate as a secondary antioxidant, 0.1% byweight of n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate asa heat stabilizer and 0.05% by weight of calcium stearate as ahydrochloric acid absorbent, per 100 parts by weight of the resin. Then,the resultant mixture was kneaded at a preset temperature of 180° C. bymeans of a conical tapered twin-screw extruder produced by Haake BuchlerInstrument Inc., to prepare an ethylene/α-olefin copolymer composition.

The ethylene/α-olefin copolymer composition had a density of 0.922 g/cm³and MFR of 1.9 g/10 min.

Preparation of film!

The ethylene/α-olefin copolymer composition obtained above was subjectedto inflation by the use of a single-screw extruder (20 mmφ.L/D=26)equipped with a die of 25 mmφ (lip width: 0.7 mm) and a single-slit airring under the conditions of an air flow rate of 90 1/min, an extrusionrate of 9 g/min, a blow ratio of 1.8, a take-up rate of 2.4 m/min and aprocessing temperature of 200 ° C., to form a film having a thickness of30 μm.

Melt properties of the ethylene/α-olefin copolymer composition andphysical properties of the film formed from the composition are setforth in Table 2.

As is evident from Table 2, the ethylene/α-olefin copolymer compositionwas excellent in flowability and moldability, and an inflation film ofhigh optical characteristics and high strength was obtained from thiscomposition.

REFERENCE EXAMPLE 1

An ethylene/1-hexene copolymer (C-1) having almost the same density andMFR as those of the composition obtained in Example 1 was prepared inthe same manner as described in Preparation Example 1 except for varyingthe gas composition. This ethylene/1-hexene copolymer (C-1). wassubjected to inflation in the same manner as described in Example 1,toform a film having a thickness of 30 μm.

Physical properties of the ethylene/1-hexene copolymer (C-1) are setforth in Table 1. Melt properties of the ethylene/1-hexene copolymer(C-1) and physical properties of the film formed from the copolymer areset forth in Table 2.

As is evident from comparison between Example 1 and Reference Example1,the film of Example 1 was excellent in the strength and thecomposition of Example 1 was excellent in the flow index (FI) withinhigh-shear region.

COMPARATIVE EXAMPLE 1

An ethylene/1-hexene copolymer (A-2) and an ethylene/1-hexene copolymer(B-2), both having been prepared in the same manner as described inPreparation Example 1 except for usingbis(1,3-dimethylcyclopentadienyl)zirconium dichloride singly as thezirconium compound in the catalyst component, were melt kneaded in sucha weight ratio as set forth in Table 2, to prepare an ethylene/α-olefincopolymer composition.

The ethylene/α-olefin copolymer composition had a density of 0.921 g/cm³and MFR of 2.0 g/10 min.

The ethylene/α-olefin copolymer composition was subjected to inflationin the same manner as described in Example 1 to form a film having athickness of 30 μm.

Melt properties of the ethyleneα-olefin copolymer composition andphysical properties of the film formed from the composition are setforth in Table 2.

COMPARATIVE EXAMPLE 2

An ethylene/1-hexene copolymer (A-3) and an ethylene/1-hexene copolymer(B-3), both having been prepared in the same manner as described inPreparation Example 1 except for usingbis(1,3-n-butylmethylcyclopentadienyl)zirconium dichloride singly as thezirconium compound in the catalyst component, were melt kneaded in sucha weight ratio as set forth in Table 2, to prepare an ethylene/α-olefincopolymer composition.

The ethylene/α-olefin copolymer composition had a density of 0.922 g/cm³and MFR of 1.9 g/10 min.

The ethylene/α-olefin copolymer composition was subjected to inflationin the same manner as described in Example 1 to form a film having athickness of 30 μm.

Melt properties of the ethylene/α-olefin copolymer composition andphysical properties of the film formed from the composition are setforth in Table 2.

As is evident from Table 2, the film of Example 1 was superior in theoptical properties to the films of Comparative examples 1 and 2,superior in the moldability (MT) and the film impact to the film ofComparative Example 1,and superior in the moldability (MT) and the flowindex (FI) within high-shear region to the film of Comparative Example2.

EXAMPLE 2

The ethylene/1-hexene copolymer (A-1) prepared in Preparation Example 1and the ethylene/1-hexene copolymer (B-3) were melt kneaded in such aweight ratio as set forth in Table 2, to prepare an ethylene/α-olefincopolymer composition.

The ethylene/α-olefin copolymer composition had a density of 0.917 g/cm³and MFR of 1.2 g/10 min.

The ethylene/α-olefin copolymer composition was subjected to inflationin the same manner as described in Example 1 to form a film having athickness of 30 μm.

Melt properties of the ethylene/α-olefin copolymer composition andphysical properties of the film formed from the composition are setforth in Table 2.

As is evident from Table 2, the ethylene/α-olefin copolymer compositionwas excellent in flow index (FI) within high-shear region andmoldability (MT), and an inflation film of high optical characteristicsand high film impact was obtained from this composition.

                                      TABLE 1                                     __________________________________________________________________________    Comonomer    Catalyst*.sup.1                                                  Code     Amount                                                                            I/II  Density                                                                           MFR    η!                                          No.                                                                              Kind  mol. %                                                                            by mol                                                                              g/cm.sup.3                                                                        g/10-min                                                                            dl/g                                                                             Mw/Mn                                         __________________________________________________________________________    A-1                                                                              1-hexene                                                                            --  8/2   0.908                                                                             0.40  2.00                                                                             2.5                                           A-2                                                                              1-hexene                                                                            4.8  0/10 0.907                                                                             0.35  1.88                                                                             3.5                                           A-3                                                                              1-hexene                                                                            --  10/0  0.909                                                                             0.46  2.30                                                                             3.1                                           B-1                                                                              1-hexene                                                                            --  8/2   0.943                                                                             180   0.68                                                                             --                                            B-2                                                                              1-hexene                                                                            1.0  0/10 0.943                                                                             165   0.70                                                                             --                                            B-3                                                                              1-hexene  10/0  0.943                                                                             170   0.68                                                                             --                                            C-1                                                                              1-hexene                                                                            2.9 8/2   0.923                                                                             2.1   1.64                                                                             2.6                                           __________________________________________________________________________     ##STR6##                                                                     __________________________________________________________________________    A-1                                                                               93.0                                                                              5.7                                                                              4.7                                                                                48                                                                              60 0.54    2.25  0.60                                       A-2                                                                               92.8                                                                              5.9                                                                              5.3                                                                                92                                                                              53 0.55    1.69  4.89                                       A-3                                                                               93.1                                                                              3.6                                                                              4.2                                                                                30                                                                              69 0.52    1.16  0                                          B-1                                                                              118.6                                                                             <0.1                                                                              --                                                                              13,000                                                                            --  0.69    --    --                                         B-2                                                                              118.6                                                                             <0.1                                                                              --                                                                              12,400                                                                            --  0.45    --    --                                         B-3                                                                              118.5                                                                             <0.1                                                                              --                                                                              13,500                                                                            --  0.44    --    --                                         C-1                                                                              114.5                                                                              2.1                                                                              1.2                                                                               212                                                                             315 --      0.81  0.03                                       __________________________________________________________________________     *1 Transition metal compound catalyst component                               I: bis(1,3n-butylmethylcyclopentadienyl)zirconium dichloride                  II: bis(1,3dimethylcyclopentadienyl)zirconium dichloride                      *2: value of 2.2 × MFR.sup.-0.84                                        *3: value of 150 × MFR                                                  *4: value of 0.03 × FI/MFR - 3.0 (In the case of less than 0, the       value is taken as 0.)                                                    

                  TABLE 2                                                         ______________________________________                                                Component  Component  Mixing Ratio                                                                          Density                                         A          B          A/B     d                                               Code No.   Code No.   (by weight)                                                                           g/cm.sup.3                              ______________________________________                                        Ex. 1   A-1        B-1        60/40   0.922                                   Ref. Ex. 1                                                                            C-1               --        0.923                                     Comp. Ex. 1                                                                           A-2        B-2        60/40   0.921                                   Comp. Ex. 2                                                                           A-3        B-3        60/40   0.922                                   Ex. 2   A-1        B-3        70/30   0.917                                   ______________________________________                                        Melt properties of Ethylene/α-olefin                                    Copolymer Composition                                                                 MFR              MT      FI                                                   g/10 min         g       s.sup.-1                                     ______________________________________                                        Ex. 1   1.9              2.2     410                                          Ref. Ex. 1                                                                            2.1              2.1     212                                          Comp. Ex. 1                                                                           2.0              1.9     520                                          Comp. Ex. 2                                                                           1.9              0.9     260                                          Ex. 2   1.2              3.8     230                                          ______________________________________                                                Physical Properties of Film                                                                     Film                                                          Haze   Gloss    Impact  Moldability                                           %      %        kg · cm/cm                                                                   *2                                          ______________________________________                                        Ex. 1     8.1    67       6,930   BB                                          Ref. Ex. 1                                                                              5.6    88       2,270   BB                                          Comp. Ex. 1                                                                             10.5   54       5,770   CC                                          Comp. Ex. 2                                                                             25.1   18       NB*.sup.1                                                                             CC                                          Ex. 2     7.6    70       NB*.sup.1                                                                             AA                                          ______________________________________                                         *1 NB = not broken (film impact > 8,500 kg · cm/cm)                  *2 Moldability                                                                AA: MT ≧ 3 g                                                           BB: 2 g ≦ MT < 3 g                                                     CC: MT < 2 g                                                             

EXAMPLE 3

825 g of the ethylene/α-olefin copolymer composition (ethylene/α-olefincopolymer composition obtained in Example 1,density: 0.922 g/cm³, MFR:1.9 g/10 min) was dissolved at 160° C. in 5.7 liters of toluene as areaction solvent.

Then, to the resultant solution were slowly added a toluene solution ofmaleic anhydride (4.13 g/250 ml) and a toluene solution of dicumylperoxide (DCP) (0.33 g/50 ml) over a period of 4 hours through differentconduits.

After the addition was completed, the reaction was further continued for30 minutes at 160° C. Then, the temperature of the system was cooled toroom temperature to precipitate a polymer. The precipitated polymer wasfiltered, then repeatedly washed with acetone and dried at 80° C. forone day and night under a reduced pressure, to obtain an aimed modifiedethylene/α-olefin copolymer composition.

The modified ethylene/α-olefin copolymer composition was subjected toelemental analysis to determine the graft amount of the maleicanhydride. As a result, in the modified ethylene/α-olefin copolymercomposition, maleic anhydride was graft polymerized in an amount of 0.2g per 100 g of the modified ethylene/α-olefin copolymer composition.Further, the modified ethylene/α-olefin copolymer composition had adensity of 0.922 g/cm³ and MFR of 1.0 g/10 min.

The modified ethylene/α-olefin copolymer composition was measured on thephysical properties such as melt properties. The results are set forthin Table 3.

Molding of a pressed sheet!

The modified ethylene/α-olefin copolymer composition was heated at 200°C. for 10 minutes by a press molding machine. Then, the composition washeld under a pressure of 100 kg/cm² for 3 minutes and was further heldunder a pressure of 100 kg/cm² for 5 minutes using a cooled pressingmachine of 20° C. to mold the composition into a pressed sheet.

The pressed sheet was measured on various properties such astransparency and adhesion strength to an aluminum 5 foil or to a 6-nylonsheet. The results are set forth in Table 3.

As is evident from Table 3, the modified ethylene/α-olefin copolymercomposition had high transparency and showed good moldability owing tohigh melt tension and high flow index. Further, the composition wasexcellent in the adhesion strength to highly polar materials such asaluminum and nylon.

                  TABLE 3                                                         ______________________________________                                                               Adhesion to                                            Modified Ethylene/α-olefin                                                                     Adherend                                               Copolymer Composition  to       to                                            MFR       Density MT     FI   Haze Aluminum                                                                             6-Nylon                             g/10 min  g/cm.sup.3                                                                            g      s.sup.-1                                                                           %    kg/25 mm                                                                             kg/25 mm                            ______________________________________                                        Ex. 3                                                                              1.0      0.922   4.1  240  51   19.5   29.0                              ______________________________________                                    

EXAMPLE 4

Preparation of an ethylene/α-olefin copolymer

Preparation of a catalyst component!

The procedure for preparing the catalyst component in PreparationExample 1 was repeated except for varying the amounts of the zirconiumcompounds to those given below, to prepare a catalyst component.

A toluene solution of bis(1,3-n-butylmethylcyclopentadienyl)zirconiumdichloride (Zr: 34.0 mmol/l): 7.4 liters

A toluene solution of bis(1,3-dimethylcyclopentadienyl)zirconiumdichloride (Zr: 28.1 mmol/l): 1.0 liters

Preparation of a prepolymerized catalyst!

The procedure for preparing the prepolymerized catalyst in PreparationExample 1 was repeated except for using the catalyst component preparedabove, to obtain a prepolymerized catalyst.

Polymerization!

Copolymerization of ethylene with 1-hexene was carried out by the use oftwo fluidized bed gas phase polymerizers of continuous type combinedwith each other in series. In the first stage, under the conditions of atotal pressure of 18 kg/cm² -G and a polymerization temperature of 75°C., to the polymerizer were continuously fed the prepolymerized catalystprepared above at a feed rate of 1.5 mmol/hr in terms of zirconium atomand triisobutylaluminum at a feed rate of 30 mmol/hr while continuouslyfeeding ethylene, 1-hexene, hydrogen and nitrogen to maintain a constantgas composition (gas composition: 1-hexene/ethylene=0.040,hydrogen/ethylene=4.0×10⁻⁴, ethylene concentration=25%) during thepolymerization.

In the second stage, under the conditions of a total pressure of 16kg/cm² -G and a polymerization temperature of 75° C., to the polymerizerwere continuously fed ethylene, 1-hexene, hydrogen and nitrogen (gascomposition: 1-hexene/ethylene=0.020, hydrogen/ethylene=16×10⁻⁴,ethylene concentration=34%).

In the first stage, the residence time was 3 hours, and a copolymer wasprepared at a rate of 60 kg/hr. The copolymer thus obtained had MFR of0.5 g/10 min, a density of 0.912 g/cm³ and a decane-soluble portionquantity at 23° C. of 0.55% by weight. In the second stage, theresidence time was 1.5 hours, and a copolymer was prepared at a rate of33 kg/hr in the second-stage polymerizer. The copolymer thus obtainedhad MFR of 1.5 g/10 min, a density of 0.922 g/cm³ and a decane-solubleportion quantity at 23° C. of 0.51% by weight.

Preparation of a film!

The ethylene/1-hexene copolymer obtained above was subjected toinflation in the same manner as described in Example 1 to form a filmhaving a thickness of 30 μm.

Melt properties and other properties of the ethylene/1-hexene copolymerand physical properties of the film formed from the copolymer are setforth in Table 4.

As is evident from Table 4, an inflation film excellent in moldability,optical characteristics and mechanical strength was obtained from thecopolymer.

COMPARATIVE EXAMPLE 3

Copolymerization of ethylene with 1-hexene was carried out by the use ofone fluidized bed gas phase polymerizer of continuous type. The catalystused herein was the same as that used in Example 4.

The ethylene/1-hexene copolymer obtained above had MFR of 1.5 g/10 minand a density of 0.922 g/cm³.

The ethylene/1-hexene copolymer was subjected to inflation in the samemanner as described in Example 1 to form a film having a thickness of 30μm.

Melt properties and other properties of the ethylene/1-hexene copolymerand physical properties of the film formed from the copolymer are setforth in Table 4.

As is evident from Table 4, the ethylene/1-hexene copolymer obtained inExample 4 was superior in the flow index (FI) within high-shear regionto that of Comparative Example 3, and the inflation film obtained inExample 4 was superior in the film impact to that of Comparative example3, although the copolymer of Example 4 was almost the same as thecopolymer of Comparative Example 3 in the MFR and the density.

EXAMPLE 5

Preparation of an ethylene/α-olefin copolymer

Polymerization!

The procedure for the polymerization in Example 4 was repeated exceptfor using the prepolymerized catalyst prepared in Preparation Example1,to obtain an ethylene/1-hexene copolymer different in MFR and densityfrom the copolymer of Example 4. The copolymer thus obtained had MFR of2.2 g/10 min, a density of 0.923 g/cm³ and a decane-soluble portionquantity at 23° C. of 0.46% by weight.

The ethylene/1-hexene copolymer was subjected to inflation in the samemanner as described in Example 1 to form a film having a thickness of 30μm.

Melt properties and other properties of the ethylene/1-hexene copolymerand physical properties of the film formed from the copolymer are setforth in Table 4.

As is evident from Table 4, an inflation film excellent in moldability,optical characteristics and mechanical strength was obtained from thecopolymer.

COMPARATIVE EXAMPLE 4

Copolymerization of ethylene with 1-hexene was carried out by the use ofone fluidized bed gas phase polymerizer of continuous type. The catalystused herein was the same as that used in Example 5.

The ethylene/1-hexene copolymer obtained above had MFR of 2.1 g/10 minand a density of 0.923 g/cm³.

The ethylene/1-hexene copolymer was subjected to inflation in the samemanner as described in Example 1 to form a film having a thickness of 30μm.

Melt properties and other properties of the ethylene/1-hexene copolymerand physical properties of the film formed from the copolymer are setforth in Table 4.

As is evident from Table 4, the ethylene/1-hexene copolymer obtained inExample 5 was superior in the flow index (FI) within high-shear regionto that of Comparative Example 4, and the inflation film obtained inExample 5 was superior in the film impact to that of Comparative example4, although the copolymer of Example 5 was almost the same as thecopolymer of Comparative Example 4 in the MFR and the density.

EXAMPLE 6

Preparation of an ethylene/α-olefin copolymer

Preparation of a catalyst component!

The procedure for preparing the catalyst component in PreparationExample 1 was repeated except for varying the amounts of the zirconiumcompounds to those given below, to prepare a catalyst component.

A toluene solution of bis(1,3-n-butylmethylcyclopentadienyl)zirconiumdichloride (Zr: 34.0 mmol/1): 5.6 liters

A toluene solution of bis(1,3-dimethylcyclopentadienyl)zirconiumdichloride (Zr: 28.1 mmol/1): 2.9 liters

Preparation of a prepolymerized catalyst!

The procedure for preparing the prepolymerized catalyst in PreparationExample 1 was repeated except for using the catalyst component preparedabove, to obtain a prepolymerized catalyst.

Polymerization!

The procedure for the polymerization in Example 4 was repeated exceptfor using the prepolymerized catalyst prepared above, to obtain anethylene/1-hexene copolymer different in MFR and density from thecopolymer of Example 4. The copolymer thus obtained had MFR of 1.2 g/10min, a density of 0.920 g/cm³ and a decane-soluble portion quantity at23° C. of 0.52% by weight.

The ethylene/1-hexene copolymer was subjected to inflation in the samemanner as described in Example 1 to form a film having a thickness of 30μm.

Melt properties and other properties of the ethylene/1-hexene copolymerand physical properties of the film formed from the copolymer are setforth in Table 4.

As is evident from Table 4, an inflation film excellent in moldability,optical characteristics and mechanical strength was obtained from thecopolymer.

COMPARATIVE EXAMPLE 5

Copolymerization of ethylene with 1-hexene was carried out by the use ofone fluidized bed gas phase polymerizer of continuous type. The catalystused herein was the same as that used in Example 6.

The ethylene/1-hexene copolymer obtained above had MFR of 1.2 g/10 minand a density of 0.919 g/cm³.

The ethylene/1-hexene copolymer was subjected to inflation in the samemanner as described in Example 1 to form a film having a thickness of 30μm.

Melt properties and other properties of the ethylene/1-hexene copolymerand physical properties of the film formed from the copolymer are setforth in Table 4.

As is evident from Table 4, the ethylene/1-hexene copolymer obtained inExample 6 was superior in the flow index (FI) within high-shear regionto that of Comparative Example 5, and the inflation film obtained inExample 6 was superior in the film impact to that of Comparative example5, although the copolymer of Example 6 was almost the same as thecopolymer of Comparative Example 5 in the MFR and the density.

                                      TABLE 4                                     __________________________________________________________________________    Comonomer      Catalyst*.sup.1                                                                    First Stage                                                          Amount                                                                            I/II MFR   η! Density                                            Kind mol. %                                                                            by mol                                                                             g/10-min                                                                           dl/g                                                                              Mw/Mn                                                                             g/cm.sup.3                                   __________________________________________________________________________    Ex. 4 1-hexene                                                                           --  9/1  0.50 2.09                                                                              2.6 0.912                                        Comp. Ex. 3                                                                         1-hexene                                                                           2.9 9/1  --   --  --  --                                           Ex. 5 1-hexene                                                                           --  8/2  0.45 2.10                                                                              2.8 0.911                                        Comp. Ex. 4                                                                         1-hexene                                                                           2.9 8/2  --   --  --  --                                           Ex. 6 1-hexene                                                                           --  7/3  0.38 2.21                                                                              3.0 0.909                                        Comp. Ex. 5                                                                         1-hexene                                                                           3.3 7/3  --   --  --  --                                           __________________________________________________________________________    First Stage                                                                    ##STR7##                                                                     __________________________________________________________________________    Ex. 4 0.55    99.6                                                                            6.4                                                                              3.9                                                                              32 75 2.46  0                                           Comp. Ex. 3                                                                         --      --                                                                              -- -- -- -- --    --                                          Ex. 5 0.48   101.0                                                                            6.0                                                                              4.3                                                                              53 68 2.14  0.53                                        Comp. Ex. 4                                                                         --      --                                                                              -- -- -- -- --    --                                          Ex. 6 0.56    93.5                                                                            7.2                                                                              5.0                                                                              49 57 2.40  0.87                                        Comp. Ex. 5                                                                         --      --                                                                              -- -- -- -- --    --                                          __________________________________________________________________________          MFR   Density                                                                            n-Decane Soluble                                                                      Tm  MT  FI                                                 g/10-min                                                                            g/cm.sup.3                                                                         Portion wt. %                                                                         °C.                                                                        g   s.sup.-1                                     __________________________________________________________________________    Ex. 4 1.5   0.922                                                                              0.51    --  3.1 176                                          Comp. Ex. 3                                                                         1.5   0.922                                                                              --      114.4                                                                             3.1 105                                          Ex. 5 2.2   0.923                                                                              0.46    --  2.0 353                                          Comp. Ex. 4                                                                         2.1   0.923                                                                              --      114.5                                                                             2.1 212                                          Ex. 6 1.2   0.920                                                                              0.52    --  4.5 213                                          Comp. Ex. 5                                                                         1.2   0.919                                                                              0.57    114.2                                                                             4.5 94                                           __________________________________________________________________________            Physical Properties of Film                                                   Haze                                                                             Gloss  Impact Strength                                                                       Moldability                                                 %  %      kg · cm/cm                                                                   *6                                                  __________________________________________________________________________    Ex. 4   8.0                                                                              69     NB*.sup.5                                                                             AA                                                  Comp. Ex. 3                                                                           4.4                                                                              89     3,950   AA                                                  Ex. 5   8.4                                                                              63     6,880   BB                                                  Comp. Ex. 4                                                                           4.6                                                                              85     3,270   BB                                                  Ex. 6   8.8                                                                              57     NB*.sup.5                                                                             AA                                                  Comp. Ex. 5                                                                           6.2                                                                              61     7,320   AA                                                  __________________________________________________________________________     *1 Zirconium compound in the catalyst component                               I: bis(1,3n-butylmethylcyclopentadienyl)zirconium dichloride                  II: bis(1,3dimethylcyclopentadienyl)zirconium dichloride                      *2: value of 2.2 × MFR.sup.-0.84                                        *3: value of 150 × MFR                                                  *4: value of 0.03 × FI/MFR - 3.0 (In the case of less than 0, the       value is taken as 0.)                                                         *5 NB: not broken (film impact > 8,500 kg · cm/cm)                   *6 Moldability                                                                AA: MT ≧ 3 g                                                           BB: 3 g > MT ≧ 2 g                                                     CC: 2 g > MT                                                             

What is claimed is:
 1. A moldable graft modified ethylene/α-olefincopolymer composition obtained by graft copolymerizing anethylene/α-olefin copolymer composition with a polar monomer, whereinthe ethylene/α-olefin copolymer composition comprises:(A1) anethylene/α-olefin copolymer in an amount of 20 to 90% by weight, whichis obtained by copolymerizing ethylene with an α-olefin of 3 to 20carbon atoms in the presence of a catalyst for olefin polymerizationcomprising (a) an organoaluminum oxy-compound and (b) at least one kindof a transition metal compound represented by the following formulab-I!:

    ML.sup.1.sub.x                                              b-I!

wherein M is a transition metal atom selected from Group IVB of theperiodic table, L¹ is a ligand coordinating to the transition metal atomM, at least two of L¹ are groups selected from a cyclopentadienyl group,a methylcyclopentadienyl group, an ethylcyclopentadienyl group and asubstituted cyclopentadienyl group having at least one substituent groupselected from a hydrocarbon group of 3 to 10 carbon atoms, L¹ other thanthe (substituted) cyclopentadienyl group is a hydrocarbon group of 1 to12 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilylgroup, a halogen atom or a hydrogen atom, and X is a valence of thetransition metal atom M, and at least one kind of a transition metalcompound represented by the following formula b-II!:

    ML.sup.2.sub.x                                              b-II!

wherein M is a transition metal atom selected from Group IVB of theperiodic table, L² is a ligand coordinating to the transition metalatom, at least two of L² are substituted cyclopentadienyl groups having2-5 substituent groups selected from a methyl group and an ethyl group,L² other than the substituted cyclopentadienyl group is a hydrocarbongroup of 1 to 12 carbon atoms, an alkoxy group, an aryloxy group, atrialkylsilyl group, a halogen atom or a hydrogen atom, and x is avalence of the transition metal atom M and which has such propertiesthat: (A-i) the density is in the range of 0.850 to 0.980 g/cm³, (A-ii)the intrinsic viscosity (η) as measured in decalin at 135° C. is in therange of 0.4 to 8 dl/g; and (A-iii) the melt tension (MT (g)) at 190° C.and the melt flow rate (MFR) satisfy the relation

    MT>2.2×MFR.sup.-0.84,

and (B1) an ethylene/α-olefin copolymer in an amount of 10 to 80% byweight, which has a density and MFR different from the ethylene/α-olefincopolymer (A1) and is obtained by copolymerizing ethylene with anα-olefin of 3 to 20 carbon atoms in the presence of a catalyst forolefin polymerization comprising (a) an organoaluminum oxy-compound and(b') a compound of Group IV transition metal of the periodic tablecontaining a ligand having a cyclopentadienyl skeleton, and which hassuch properties that:(B-i) the density is in the range of 0.850 to 0.980g/cm³, and (B-ii) the intrinsic viscosity (η) as measured in decalin at135° C. is in the range of 0.4 to 8 dl/g.
 2. The graft modifiedethylene/α-olefin copolymer composition of claim 1 wherein theethylene/α-olefin copolymer (A1) has the following properties:(A-i) adensity in the range of 0.890 to 0.935 g/cm³ ; (A-ii) an intrinsicviscosity (η) as measured in decalin at 135° C., in the range of 1.25 to8 dl/g; and (A-iii) a melt tension (MT (g)) at 190° C. and melt flowrate (MFR) satisfying the relation:

    7.5×MFR.sup.-0.84 >MT>2.5×MFR.sup.-0.84 ;

and the ethylene/α-olefin copolymer (B1) has the following properties:(B-i) a density in the range of from 0.910 to 0.960 g/cm³ ; and (B-ii)intrinsic viscosity (η), measured in decalin at 135° C., in the range of0.5 to 1.23 dl/g.
 3. The graft modified ethylene/α-olefin copolymercomposition of claim 2 which comprises from 40 to 75% by weight of theethylene/α-olefin copolymer (A1) and from 25 to 60% by weight of theethylene/α-olefin copolymer (B1).
 4. The graft modifiedethylene/α-olefin copolymer composition of claim 3 wherein theethylene/α-olefin copolymer which is graft copolymerized with a polarmonomer has the following properties:(ii) a density in the range of from0.890 to 0.95 g/cm³ ; (iii) a melt flow rate (MFR) measured at atemperature of 190° C. and with a load of 2.16 kg, in the range of 0.2to 50 g/10 min.; (iv) a melt tension (MT(g)) at 190° C., and the meltflow rate (MFR) satisfying the relation:

    MT>=2.2×MFR.sup.-0.84 ;

(v) a flow index (FI (1/sec)) defined by a shear rate which is givenwhen a shear stress at 190° C. reaches 2.4×10⁶ dyne/cm² which is morethan 130 times the melt flow rate (MFR); (vi) the temperature (Tm (°C.)) at which the endothermic curve of the composition measured by adifferential scanning calorimeter shows a maximum peak which has thefollowing relationship with the density (d):

    TM<450×d-297;

(vii) the quantity fraction (W (percent by weight)) of ann-decane-soluble component at room temperature which has the followingrelationship with the density (d):when

    MFR≦10 g/10 min.:

    W<60×exp(-100 (d-0.88))+0.1;

and when MFR>10 g/10 min.:

    W<80×(MFR-9)×exp (-100 (d-0.88))+0.1.